Evaluating Attractants for Live-Trapping Armadillos

Source(s): Michael T. Mengak

In the past 50 years, the range of the nine-banded armadillo (Dasypus novemcinctus) in the south has been rapidly expanding, bringing armadillos increasingly into conflict with suburban landowners. When foraging, armadillos often uproot ornamental plants. Their rooting also destroys gardens, lawns and flower beds. Their burrowing can damage tree roots and building foundations.

Most armadillo damage is caused by their feeding habits. Armadillos dig shallow holes, 1-3 inches deep and 3-5 inches long, as they search for soil invertebrates. A recent survey of Georgia county extension agents by scientists at the University of Georgia found that 77.6 percent of all agents reported receiving complaints or requests for information on armadillos. Armadillo-related inquiries made up 10.1 percent of all inquiries for all agents across the state, surpassing even the white-tail deer.

Armadillos are often assumed to destroy nests of ground- nesting birds. Armadillo diets have been studied in several states including Alabama, Louisiana, Texas, Georgia, Arkansas and Florida. According to these studies, vertebrate matter, especially bird eggs, made up a minor portion of their diet. The armadillo’s diet often consists of more than 90 percent insects, grubs and earthworms. Based on these studies, it seems that claims of armadillos being significant nest predators are unfounded. Some authors warn, however, that armadillos merely break eggs open and lick out the contents. When this happens, little evidence remains in their stomachs, making detection of egg predation using stomach content analysis almost impossible. Miniature video surveillance cameras monitoring quail nests at Tall Timbers Research Station in Florida have documented this behavior in wild armadillos. The study found that armadillos may be more significant quail predators than previously accepted. They were responsible for destroying up to 26 percent of all quail nests.

Armadillos are not protected under Georgia wildlife regulations (DNR website www.georgiawildlife.com). They may be hunted or trapped year round without limit. Removal by shooting can be an effective control method, but this may not be safe or desirable for suburban landowners. Many suburban landowners would rather have animals trapped and relocated. Other control methods are available, such as habitat modification and exclusion, but these methods are often impractical, expensive or ineffective.

Our objective was to test several different lures or baits for live-trapping nine-banded armadillos. We used cage traps, hoping they could be a practical alternative to lethal removal for suburban landowners.


We trapped armadillos, using 10 x 12 x 32 inch Tomahawk wire cage traps, from April to July, 2004, at the Joseph W. Jones Ecological Research Center in Newton, Georgia. Traps were placed in areas with abundant armadillo sign. Since we were primarily interested in evaluating the attractants we avoided placing traps directly over burrows, where armadillos may be forced into traps. We tested the effectiveness of several baits and lures, including:

  • Live night crawlers
  • Live crickets
  • Rotten chicken feed
  • Whole eggs
  • Rotten eggs
  • Bananas
  • Marshmallows
  • Sardines
  • Vanilla wafers
  • Moistened soil
  • “Armor plate,” a commercially available lure

In addition, we tested two types of unbaited traps:

  1. an unbaited trap with “wings” consisting of two 2- inch x 6-inch boards and 6 feet long attached at one end of the trap to funnel the armadillo into the trap, and
  2. an unbaited trap without wings.


In trapping studies, scientists compare data by calculating an index called trap nights. One trap night equals one trap set for one night. Ten trap nights equal one trap set for ten nights or ten traps set for one night. In our study, we had 1,332 trap nights. We captured only 10 armadillos or an average of one armadillo every 132 trap nights. This number is quite low. Of the 11 attractants we evaluated, most of them (nightcrawlers, chicken feed, whole eggs, bananas, marshmallows, sardines and vanilla wafers) had 0 captures. Capture success was too low for any meaningful statistical comparisons of attractants. However, when all baited traps (63% of trap nights) were compared with the unbaited traps (37% of trap nights), there was no significant difference in capture success. Only four armadillos were captured in traps with baits or lures. Six armadillo were captured in unbaited traps. Of these six, four were caught in unbaited traps with wings.


Given that capture success was quite low, it is unlikely that trapping is an effective method of quickly reducing local armadillo populations. Until an effective attractant can be found, lethal removal by shooting remains the most effective solution. If live-trapping and relocation are chosen as control measures, however, the use of any of the attractants tested is unnecessary. Armadillos in this study were just as likely to enter a baited trap as an unbaited trap. It is likely that the armadillos we did capture randomly walked into the traps and were not necessarily attracted.

This suggests that if armadillos are to be captured, trap placement is much more important that attractant selection. Homeowners and others attempting to live trap armadillos should carefully select a trapping location. It is likely that a trap (even one without bait) with wings placed near an active burrow will be the most effective method for capturing individual nuisance animals. Homeowners and others can place traps near natural barriers or fences such as the walls of patios, edges of buildings or landscaping features; or near natural fences such as fallen trees. The use of baits and attractants does not appear to increase trap success.

Individuals needing more information are encouraged to contact the author by email at mmengak@warnell.uga.edu or by phone (706-583-8096).

Center Publication Number: 198

Snakes and Their Control

Source(s): Michael T. Mengak

No other creatures provoke such simultaneous conflicting feelings as do snakes. We are at once attracted and repelled, intrigued by them and their habits and, at the same time, certain people are seized by an almost overwhelming urge to kill. As with any wild animal, caution is advised. Homeowners, hikers, hunters, children and others should not approach or threaten any wild animal, and snakes are no exception.


A major reason many fear snakes is that some are venomous. Of the more than 50 kinds in Georgia, however, only 6 species or about 12 percent are venomous. Our venomous species are Eastern Coral Snake (Micrurus fulvius), Copperhead (Agkistrodon contortrix), Cottonmouth (Agkistrodon piscivorus), Pygmy Rattlesnake (Sistrurus miliarus), Timber Rattlesnake (Crotalus horridus), and Eastern Diamondback Rattlesnake (Crotalus adamanteus).

Fortunately, snakebite is a rare accident. Fewer people are killed by snakes than by lightning. The best defense is knowledge; learn to recognize venomous species. Snakes of Georgia and South Carolina by Whit Gibbons and Patricia West (editors) is a good reference for snake identification. This booklet is available for $5 from the Savannah River Ecology Laboratory in Aiken, SC, the University of Georgia Cooperative Extension Service or your local county extension agent.

Snakes feed on a wide variety of small creatures and are very particular about what they eat. Some species eat only warm-blooded animals such as rodents and birds. Others may eat only toads and frogs. Large land-dwelling snakes are likely to feed on rodents, birds and their eggs, lizards, other snakes, toads and frogs. Aquatic snakes feed primarily on fish and amphibians. Small snakes are likely to eat mice, frogs, toads, earthworms, slugs and soft-bodied insects. Thus snakes are part of the natural system. Many of the things they eat are considered pests, so knowledgeable people spare harmless snakes that live in their yards.

Venomous snakes are another matter. In most circumstances, they should be removed. Be careful – a snake can strike half its length or more. Even when the snake is dead, its reflex movement can result in a bite if handled carelessly. Bites by venomous snakes need prompt medical attention. The bites of non-venomous species can be treated with soap, water and antiseptic.

Any non-venomous snake can be safely removed from a building by using a long-handled broom to gently brush the animal into an empty trash can. Place the lid on the can and take the snake to a wooded area away from any homes and carefully release it.

Refer venomous snakes in buildings to the Wildlife Resources Division of the Department of Natural Resources. Most people are bitten when they try to kill a snake. This only causes the snake to defend itself the only way it can.

The following plan of action will reduce the severity of a snake bite:

  • Stay calm. The snake may be non-venomous, but if it’s venomous, excitement hurts, not helps.
  • Have someone kill the snake so it can be identified. Use extreme caution. Most snakebites occur when attempting to kill the snake.
  • Get to competent medical help as quickly as possible.
  • Ask your doctor what he or she advises regarding snake bite – before it happens.

What attracts snakes to dwellings? If the house is surrounded by natural countryside with rock piles, streams and swamps nearby, snakes will appear from time to time. Naturalistic landscaping, rock gardens, weedy places, piles of boards and debris, deteriorating outbuildings and other similar things may harbor snakes.

Since there are no chemical poisons or effective repellents registered for snake control, the best way to make yards and outbuildings unattractive to snakes is to clean up and clean out. Snakes cannot hear sound, so auditory repellents are ineffective.

The first step is to ensure that there are no openings in dwellings or other structures where snakes can enter. Since snakes can get through very small holes (about the size of a dime), a careful inspection is necessary. For additional information, check with your local county extension office.

At the same time you are keeping snakes out of the house, take steps to make the rest of the premises unattractive. Look at the surroundings as if you were a snake. Are there rodents or other sources of food? Are there places to hide? If the answers are “yes,” plan a program to remove food and cover.

  • Control rodents if they are present.
  • Get rid of debris.
  • Remove brush and leaf piles.
  • Place stacked materials 12 or more inches above the ground or floor and away from walls.
  • Keep the space beneath structures and stacks clean.
  • Keep shrubbery and other plantings away from foundations and walls.
  • Keep shrubbery clean and free of debris. Keep lawns closely mowed. Fill unwanted depressions.
  • Keep stream or pond banks clean and clipped.

These practices will reduce but not eliminate the possibility of finding snakes. Remember, it is best to remove items that a snake would find attractive. Do not try to handle them.

Enjoy their presence by observing them from a safe distance. They are highly evolved predators that have a natural role in the environment. Especially remember that the vast majority are secretive, harmless to humans and beneficial in controlling mice, insects and other pests.

Center Publication Number: 212


Source(s): Michael T. Mengak

Copperheads are venomous snakes and members of the pit viper family. Pit vipers have a heat-sensing organ located between the eye and the nostril. This organ is useful in locating food by detecting the body heat of prey species. Copperheads are not generally aggressive and rarely injure people. They are secretive but valuable members of the wildlife community. Copperheads range throughout most of Georgia and occupy a variety of habitats.

Two Copperhead snakes
Two Copperhead snakes


  • Vipers(Family Viperidae)
    • Pit Vipers(Subfamily Crotalinae)
      • Copperheads and Cottonmouths(Genus Agkistrodon)

There are two species in the genus Agkistrodon — the copperhead (Agkistrodon contortrix, with five subspecies) and the cottonmouth (Agkistrodon piscivorus, with three subspecies). Two subspecies of copperhead — the northern copperhead, A. c. mokasen, and the southern copperhead, A. c. contortrix — are found in the state with a wide area of overlap in central Georgia. The other three subspecies occur generally west of the Mississippi River.


Both northern and southern copperheads are common in suitable habitat. The copperhead is not listed as protected by the State of Georgia Natural Heritage Program. A significant threat to the copperhead is malicious killing by humans. Perhaps the most significant threat to the copperhead is the loss of habitat caused by various human activities.


Southern Copperhead: The southern copperhead has pale beige to almost pink background color (called the “ground color”). It has 13 to 20 wide, dark bands along its length in the shape of an hourglass. The two halves of the hourglass often do not meet along the spine. The head is a copper color. The young look similar but have a sulfur yellow tail. Southern copperheads are stout-bodied snakes, usually 24 to 36 inches long as adults. The longest specimen ever reported is 52 inches long (4 feet, 4 inches). The southern subspecies is generally larger than the northern subspecies. Northern Copperhead: The northern copperhead’s ground color is darker than the southern subspecies. The color varies from brown to tan but has the familiar hourglass bands, which generally do meet along the spine. It also has the copper-colored head, and young specimens have the yellow tail. Most adult northern copperheads are 26 to 34 inches long, and the record is 53 inches (4 feet, 5 inches).


In Georgia, the northern copperhead is found in the mountainous counties of north Georgia. The southern copperhead is found below the fall line but not in the most southeastern counties along the Florida line. In southwest Georgia, it is found along the Alabama-Georgia border extending into two counties in north Florida. In the Piedmont, the two subspecies overlap in distribution, and specimens take on a range of appearances falling between the typical patterns for each subspecies.

Form and Function

Both the northern and southern copperhead has 23 to 25 rows of dorsal scales that are weakly keeled. The anal plate is not divided. There is a single row of caudal scales. Both possess hollow fangs that are retractable and located in the front of the mouth. The fangs are up to ½ inch long and probably not capable of penetrating the average boot. Average adult weight in a Kansas study was 10.5 ounces. Their preferred body temperature ranges from 78.8 degrees to 84.2 degrees F.

All North American snakes use the environment to warm their bodies. Snakes are called “cold-blooded,” but a better term to describe this characteristic is “exothermic,” meaning they use external rather than metabolic heat for warmth. A copperhead’s core body temperature can vary throughout the year from 39.2 degrees to 105.8 degrees F. Body temperature also varies daily. The snake cools overnight and must use the sun’s heat to warm itself during the day. The venom attacks muscle and blood systems. Bites are painful, but this snake has the least toxic venom of all venomous snakes in the United States. Fatalities are extremely rare.


Reproduction: Copperheads can mate in both fall and spring. They are capable of breeding every year, and give birth to live young between July and August. As few as 2 or as many as 17 young are produced, but the typical litter size is 6 to 9 young. The young are 8 to 10 inches long at birth and receive no parental care. Up to 60 percent of the females in a population may carry young in a year. Generally, females begin breeding at 3 years old. Larger and presumably older females are more likely to breed, but good health and high-energy reserves or body fat may be important in determining which females breed. Larger individuals do most of the breeding. Clutch size is larger in years with higher than average precipitation.

Female copperheads may gather in specific areas prior to giving birth. These areas are called “birthing rookeries.” We do not know how many females gather together in this manner. Gravid females do not feed while carrying young. Males usually outnumber females in both the general population and in the litter, but we don’t understand why this occurs. Feeding: Copperheads are predators near the top of their food chain. They are ambush predators, generally lying in wait for a meal. Copperheads typically feed on mice and often take the young while they are still in the nest. These predators are known to also eat frogs and toads, insects (like cicadas), caterpillars, salamanders, small birds and shrews. They can survive during the summer on just one meal every three weeks. Of course, they survive all winter without eating. Studies show that copperheads may consume twice their body weight in prey per year. They can survive on as few as eight meals during the active season. Generally, they consume 1.25 to 2 times their body weight per season. Prey items average 20 percent of body weight.

A study in Kansas found that prairie voles were the most commonly eaten prey and cicadas ranked second. Interesting prey items identified from copperhead stomachs included hawk moth larvae and a box turtle. Copperheads eat more than 30 different prey items. Young probably eat a different array of items than adults. For example, the young may eat insects, caterpillars and small frogs while the adults take more mice and birds. Young are known to use their yellow tails as lures to attract frogs and toads to within striking distance.


Copperheads often lay motionless waiting for prey to wander within range. Copperheads are pit vipers and use their heat-sensing pit to locate prey and guide their strike. The pit helps them locate warm-blooded prey after it has been bitten. The snakes also find the envenomed prey using their sense of smell.

They are not aggressive snakes and are often described as lethargic. They rarely strike unless stepped on or handled. Copperheads are most active at dawn and dusk between March and October. During the winter, they den alone or with other copperheads and rattlesnakes. They will often use the same den site for many years. They are inactive in cold weather but are not true hibernators. Copperheads are almost entirely terrestrial but swim well and probably disperse across aquatic habitats.

Copperheads are nocturnal during the summer or warmest months and shift to a diurnal activity pattern during cooler months in spring and autumn. This reflects their need to bask in the sun on cooler days in spring and autumn and to avoid the hottest part of the day in summer. Fighting between males may occur during the breeding season. The general pattern for copperheads is for two males to approach one another, raise their upper bodies off the ground, and try to push the rival to the ground. The male that pins his rival’s head to the ground is the dominant individual. The whole process is like the children’s game of “thumb wrestling.” Biting has never been reported during these wrestling bouts.


You might find a copperhead in almost any upland habitat. Northern copperheads are found in rocky areas and wooded hillsides. They are often found around sawdust piles, slab piles or rotting buildings. They are also found along wooded edges and brushy areas. Power line rights-of-way make excellent habitat if not mowed. Southern copperheads seem to prefer low-lying areas near streams and swamps, and are often confused with the cottonmouth water moccasin, which is larger (heavier-bodied) and readily swims. Copperheads prefer to avoid the water. Wooded areas with brush piles, fallen trees or logs are good habitat.


Copperheads occasionally fall prey to kingsnakes. Hawks, owls or wild pigs may consume them occasionally, but they do not hunt for them. Humans are their greatest threat; we destroy their habitat and kill them outright.


One northern copperhead was documented to have survived 29 years and 10 months, but few attain this age. One study marked and released several adult copperheads and found them, one year later, within 100 yards of their release site. Their typical home range is unknown in Georgia but, in general, we assume they wander little except in search of mates. Copperheads are the upland ecological equivalent of cottonmouths. One researcher used the pattern of complete and incomplete hourglass markings to identify individuals.


Populations may average 2.5 to 4 copperheads per acre in suitable habitat with adequate prey.


Copperheads do not transmit diseases to humans. Venomous snakes, however, should never be handled by anyone other than an expert.

Economical Value

Copperheads have no direct economic value to humans. Their skins have been used to make leather for decorative belts and hatbands. They act as predator control for mice and rats, and are thus beneficial to humans, providing a net economic gain by their presence.


They cause no direct damage to human crops or livestock.

Medicinal Use

They have no direct medicinal value. Recently, however, there has been increased interest in the pharmacological benefits of snake venom. In a recent 10-year study, 308 copperhead bites were reported. Not a single person died from the copperhead bite.

Legal Aspects

Copperheads are unprotected in Georgia.

Control to Reduce

Populations can be reduced around human structures by removing preferred habitat such as rock piles, woodpiles, slab piles, sawdust piles and abandoned buildings. Keep grass and weeds trimmed or mowed near dwellings, barns and other buildings.

Management to Enhance

Generally reversing the methods of control would provide habitat for these beneficial predator.

Human Use

Native American use — none. Colonists’ view — none.

Center Publication Number: 192

Chipmunks and Their Control

Source(s): Michael T. Mengak, Ph.D., Associate Professor and Wildlife Outreach Specialist, Warnell School of Forestry and Natural Resources, The University of Georgia.

The Eastern Chipmunk is one of the smaller members of the squirrel family, measuring 8 to 10 inches long. Chipmunks are primarily ground dwellers, but they do climb trees and shrubs for food and protection when necessary. They may be identified by the three dark dorsal stripes on the otherwise reddish-brown coat and by its habit of running with its tail sticking straight up in the air.

Chipmunks and Their Control

Chipmunks and their Behavior

Chipmunks are quick in movements and very alert to danger. They prefer open wooded areas with plenty of food-producing trees and bushes. Food and protection offered by shrubbery, flowers, gardens and various types of landscaping attract chipmunks; and it is in these conditions that most problems arise. The cute, playful little creature then becomes a pest that threatens the appearance and the well-being of a home.

The Eastern Chipmunk has an extensive burrow system that may be 30 feet or more in length with one or more hollowed out cavities where young are reared. Openings are usually at the bases of stumps or fallen logs or beside large stones or walls. Entrances and exits of the burrow system are kept free of excavated dirt.

Chipmunks eat grain (corn), nuts (acorns), seeds (sunflower or other seed in a bird seed mix), mushrooms, insects (caterpillars) and some carrion (dead animal tissue), although this is a rare item in their diet.


Chipmunks are territorial and rarely become abundant enough to cause a lot of damage. Individuals will gnaw into bags containing dog food or bird seed. They will also dig up and consume flower bulbs. Occasionally they will gnaw the bark from shrubbery.


Naphthalene crystals (“mothballs”) may repel chipmunks from sheds, attics or summer cabins. The quantity required is usually so great that the odor is offensive to humans. There are no registered repellents for chipmunks. Taste repellents containing bitrex, thiram or ammonium soaps of higher fatty acids can be applied to landscape plants. Products such as Ro-Pel®, Hinder®, Big Game Repellent® or This-1-Works® are commercially available from garden supply stores, feed stores and forestry catalogs. There are no fumigants or toxicants registered for controlling chipmunks.


Trapping is the easiest method to control chipmunks. The large wooden base snap traps used in rat control are effective in chipmunk control. Peanut butter alone or mixed with oatmeal makes good bait. Place traps along runways at burrow openings or in other areas of chipmunk activity. Place snap traps perpendicular to the wall or near burrow entrances. Homeowners can use live traps such as Havahart (No. 0) or Tomahawk (No. 102). Garden and feed stores generally sell these traps.


Exclude chipmunks from buildings whenever possible. Seal holes where gas lines, cooling lines or cable TV enter the house. Use caulking or ¼ inch welded wire. Attach a homemade screen to the bottom of a clothes dryer vent if the vent is near the ground.


If safe to do so, shooting can be effective. Use only a .22 caliber rifle with pellets or an air rifle (BB gun). Check local ordinances. It is often illegal to discharge any firearms inside city limits.

Legal Status

ALL non-game wildlife is protected in Georgia. Therefore, it is illegal to kill any species unless specifically permitted by regulations such as hunting and fishing laws. Check with your local conservation office. Generally, homeowners can protect their property from mammals causing or about to cause damage. This does not allow citizens to kill wildlife out of season or in violation of federal, state or local laws or ordinances. Contact police or local Wildlife Resource Division personnel.

Reviewer(s): Michael T. Mengak, Ph.D., Associate Professor and Wildlife Outreach Specialist, Warnell School of Forestry and Natural Resources, The University of Georgia, July 2006.

Center Publication Number: 211

Using Milorganite® As A Deer Repellant

Source(s): Michael T. Mengak

A growing human population is leading to increased land development. Many home owners maintain gardens and landscapes around their homes. Often, wildlife and humans come into contact with each other, resulting in damage to human property. Often in these cases, intensive deer management is needed.



White-tailed deer provide aesthetic and economic value, but deer can cause a variety of negative economic impacts. Deer can damage personal property, agronomic crops, landscape plantings, and food plots, and they serve as a host for diseases common to livestock and humans. Unlike some nuisance animals (fire ants, termites or rats, for example), deer cannot be casually eliminated when conflicts arise. Landowners are often expected to carry the entire burden of support for this public resource. Deer damage control can be a difficult social and political problem as well as a biological and logistical one. Scare devices, repellents and shooting are all considered effective strategies to control deer damage.

Many homeowners would like an inexpensive but effective control method to safety reduce deer damage. Repellents are often used intensively around orchards, gardens, ornamental plants and agronomic crops. New repellents continue to enter the market, but their effectiveness varies. Success is determined based on the reduction of damage, not total elimination. Repellents generally rely on fear, pain, taste or conditioned avoidance to change deer behavior. Three methods used to deliver repellents: incorporated into the plant (systemic delivery), spread throughout an area (area delivery), and applied to the plant (contact delivery). The effect of repellents varies depending on several factors including deer density, alternate food sources and changes in plant palatability. Milorganite® has been suggested as an area repellent for use in the spring and summer in Georgia to control deer damage. We tested the effectiveness of Milorganite® on ornamental plants. The specific objective of this study was to determine the effectiveness of Milorganite® as a temporary deer repellent when applied to established ornamental plants during the summer.

About Milorganite®

In 1913, the legislature in Wisconsin passed an act to create a sewage commission responsible for cleaning up the waterways. During the same year, a chemist in Birmingham, England, was conducting experiments with the biosludge in sewage. The Milwaukee Sewage Commission adopted this new process for use on December 31, 1919. Jones island, on the shore of Lake Michigan, was chosen as the site of the world’s first large-scale activated sludge treatment plant, the Jones Island Wastewater Treatment Plant. The main purpose of the Jones Island plant was to produce clean water, but they were faced with the problem of disposing of the biosolids left from the activated sludge process. The Milwaukee Metropolitan Sewerage District (MMSD) established a fellowship at the University of Wisconsin College of Agriculture to investigate uses of activated sludge as fertilizer. O. J. Noer was the primary investigator. After experimenting with field crops and vegetables, Noer focused on the use of the organic fertilizer on lawns. Based on his research, Noer concluded that the organic, slow release fertilizer can be safely applied to plants, without the risk of burning, while providing long-lasting results. The trade name, Milorganite®, was derived from MILwaukee ORGAnic NITrogEn. This product is often used for soil amendment purposes rather than as a fertilizer because of the low Nitrogen-Phosphorus- Potassium (N-P-K) values of 6-2-0. The cost 40-pound bag usually runs from $7.00 to $10.00. Milorganite® is commercially sold by fertilizer dealers throughout the United States.


Research was conducted on the Berry College campus north Georgia. Deer density in the area was estimated by Georgia Department of Natural Resources to be 35-50 deer per square mile. The campus contained two research sites: Campus site and Oak Hill Garden site. At the Campus site, test plants were small and we counted the number of terminal buds prior to planting. Then, at approximately seven-day intervals, we again counted the number of buds to determine the extent of deer damage. The difference in number of buds was an index of deer damage. At the Oak Hill Garden site, the chrysanthemums were larger with abundant buds so we counted those bud bites at approximately seven-day intervals. A bud bite was recorded if the flower bud was removed from the stalk. All bites were assumed to be due to deer. We also measured the mean plant height for each plant at each site.

Campus Site

Chrysanthemums (C. morifolium var. Sunny Linda) were planted in three plots at the Campus site. The plots were separated by about 400 yards. Each plot contained a row of 10 control and 10 treatment plants 1 foot apart. Rows of the control and the treatment plants were separated by 9 feet. Prior to planting, all terminal buds were counted, and plants were assigned to respective locations based on the number of terminal buds. Thus the total initial numbers of available terminal buds were similar for each plot. The treatment plants received an application of Milorganite® equal to 0.25 pounds (4 oz) per plant. Milorganite® was applied the same day of planting to minimize any pre-test damage done by deer. After planting, the number of existing terminal buds/blooms and plant height to the highest terminal bud (in inches) was recorded for 35 days. Milorganite® was weighed and spread by hand around each plant.

Oak Hill Garden Site

The Oak Hill Garden site was planted with approximately 1,000 chrysanthemums among three plots within established formal garden areas. Each plot contained 20 control and 20 treatment plants. Spacing between mums was similar to the Campus site. However, because of the orientation of the formal gardens, distance between respective control and treatment plants was 30 feet at two of the plots and 60 feet at the third site. The treatment plants received application rate of 4 ounces per plant of Milorganite®. Because of the level of plant maturity, we counted the number of bites to terminal flower buds and measured plant height to the tallest terminal bud (inches) for each plant during a 28-day period.


Campus Site

The average number of terminal buds for each plant across the three plots prior to planting was 72.10(treatment) and 72.23(control). The average plant height for all plants was also similar(7.5-8.0 inches). Throughout the 35-day trial, the number of terminal buds that remained on the Milorganite® treated plants significantly exceeded the controls. The presence of a greater number of terminal buds at days 21 and 28 compared to the numbers recorded immediately prior to the opportunity to grow due to limited browsing damage. Average plant height was consistently and significantly higher for the Milorganite® treated mums as compared to respective controls following the initial planting.

Oak Hill Garden Site

The average number of terminal bites was consistently greater on the untreated control plants than on the Milorganite treated plants over the 28 day observation period. While damage recorded as the removal of terminal buds (terminal bud bites) occurred for both treatment and controls, plants treated with Milorganite® had fewer average terminal bud bites. Because of the maturity of the chrysanthemums used at these sites, changes in height would be expected to be more of a function of degree of deer damage as compared to plant growth. While number of terminal bud bites was lower (meaning more buds were unbrowsed) for the treated mums throughout the 28-day trial, average plant height decreased on days 7 and 14 before returning to heights similar to the controls.


From these results, we concluded that Milorganite® has potential as a deer repellent for ornamental plants. Though the repellent did not eliminate deer damage, it reduced the overall impact. The effectiveness of a repellent is highly dependent on climatic conditions, deer density, and resource availability. High deer densities and low resource availability may reduce the efficacy of Milorganite® as a repellent. Reduction of plant damage may further be improved if Milorganite® is reapplied when deer damage is initially observed. Further research involving different application rates and different plant varieties will prove useful in determining the deer’s tolerance level to Milorganite®.

Center Publication Number: 193

Using Milorganite® to Temporarily Repel White-Tailed Deer From Food Plots

Source(s): Michael T. Mengak


Wildlife managers use food plots to increase a property’s value to wildlife. These plantings provide supplemental forage to wildlife during periods when native vegetation is less abundant or lacks nutritional quality. Because deer often prefer fertilized food plot plants to naturally available plants, however, over-browsing can damage food plots before they become sufficiently established.


Deer over-browsing reduces overall production of food plots and often leads preferred plants being replaced by less desirable invasive plants. Managers often blame poor seed or soil quality for food plot failures when deer over-browsing during establishment is the real reason for less desirable results. The only way to ensure that vigorous food plots are available to wildlife during critical periods is to prevent deer over-browsing during establishment. This is particularly true when considering summer food plots because many summer annuals become damaged and die when deer browse during early vegetative growth. Therefore, when deer are abundant on a property, managers are wise to protect summer food plots from browsing until they are adequately established to withstand browsing damage.

Repellents are often used to deter deer damage to orchards, gardens, ornamental plants and agronomic crops. Repellents generally rely on fear, pain, taste or conditioned avoidance to discourage deer browsing. Odor and/or taste-based repellents may be applied to individual plants (systematic and contact deliveries) or spread throughout an area that contains multiple plants (area delivery). New repellents continue to enter the commercial market, but their efficacy varies depending on several factors including deer density, available food resources and seasonal changes in plant palatability. Milorganite® has been suggested as an area delivery repellent for use in the spring and summer in Georgia to control deer damage to multiple plantings.

We tested the efficacy of Milorganite® as an area delivered repellent to temporarily reduce deer damage to soybeans (Glycine max) planted as supplemental summer forage for wildlife. The specific objective of this study was to determine if Milorganite® treatments would provide newly germinated soybean plants with protection from deer browsing until they were sufficiently established to survive damage.

About Milorganite®

In 1913, the Wisconsin legislature passed an act to create a sewage commission responsible for cleaning up the waterways. During the same year, a chemist in Birmingham, England, conducted the first experiments to focus on purifying wastewater containing biosludge from human sewage. The Milwaukee Sewage Commission adopted this new process for use on December 31, 1919. The world’s first large scale wastewater treatment plant was constructed on Jones Island, near the shore of Lake Michigan.

The purpose of the Jones Island facility was to produce clean water from water containing human sewage. Although they achieved this task, they soon realized the difficulty of disposing of large amounts of biosolids, a product of the water purification process. To help solve the problem of biosolid disposal, the Milwaukee Metropolitan Sewerage District established a fellowship at the University of Wisconsin College of Agriculture to study the value of biosolid sludge as a fertilizer product. Professor O. J. Noer was the primary investigator. After experimenting with field crops and vegetables, Dr. Noer focused on the value of this organic fertilizer to residential lawns. Based on his research, Dr. Noer concluded that processed biosolid sludge was an effective organic, slow release fertilizer that could be safely applied to a variety of plants.

The trade name, Milorganite®, was chosen for the product. The name was derived from MILwaukee ORGAnic NITrogEn. Today, this product is often used for soil amendment purposes rather than a fertilizer because of the low Nitrogen-Phosphorus-Potassium (6-2-0) components. Milorganite® is relatively inexpensive when compared to other commercially available fertilizers and is distributed by fertilizer dealers throughout the United States.


Our research was conducted on five properties in the Piedmont Physiographic Region of north Georgia. We did not estimate deer population density but believed deer density on each property ranged from 30-50+ deer per square mile. We did not measure composition of native plant communities or abundance of individual plant species but did recognize that differences might have existed. On each property, we selected two 0.2- hectare plots (control/treatment) separated by 15-300 meters of natural vegetation based on various site characteristics. Before planting soybeans, we applied fertilizer and lime to each plot according to the soil test recommendations provided by the University of Georgia Soil Test Laboratory, Athens, Ga.

Each plot was plowed and smoothed before we used a no-till drill to plant 60 pounds/acre of soybean seeds. When soybean plants began to emerge from the seedbed, we used the seed spreader on a tractor to broadcast 240 pounds per acre of Milorganite® to each plot. Once soybean plants were sufficiently emerged (about 1 inch tall) in a plot, we randomly selected 100 plants from each of five rows (500 plants) as a sub-sample to include in bi-weekly monitoring. We monitored the estimated amount of deer browsing damage to the subsample of soybean plants at each plot. We observed each of the 500 plants on each plot. If the plant had any evidence of browsing or if the plant was completely gone, we scored it as “browsed.” Otherwise, we scored it as “unbrowsed.” We collected data for up to 37 days after first plant emergence.


We observed location related (i.e., property) differences in percentage of soybean plants browsed during the 37-day monitoring period. The mean percentage of plants browsed among the five treatment and control sites 3 days after emergence was 23.9 percent and 54.4 percent, respectively. The treatment sites on days 6, 12, 20 and 30 had an average percentage of plants browsed of 33.3 percent, 40.2 percent, 59.2 percent and 80.2 percent, respectively. On the same days, the control sites (no Milorganite®) had an average percentage of browsed plants of 81.7 percent, 96.6 percent, 99.6 percent and 100 percent, respectively.


We concluded that Milorganite®, when broadcast over newly emerging soybeans, is an effective temporary deer repellent, which reduces negative effects of deer browsing and benefits wildlife food plot establishment. The repellent does not eliminate deer damage, however, and efficacy varies by location. Although we did not measure environmental differences among locations, we believe weather, deer density and alternative food source availability likely influence locationspecific efficacy. Extreme weather conditions coupled with high deer densities and low resource availability may reduce the efficacy of Milorganite® as a repellent. Reduction of deer damage may further increase if Milorganite® is reapplied at day 14, as suggested by the figures 3 and 4. Further research involving different application rates will prove useful in determining the deers’ tolerance level to Milorganite®. Our results suggest that landowners, farmers and sportsmen may be able to establish large-seeded legumes like soybeans in a food plot if Milorganite® is applied at planting but before damage begins. Once the plants are established, further treatment with a repellent is not necessary and soybeans are an excellent food for deer.

Individuals needing more information are encouraged to contact the author by email at mmengak@warnell.uga.edu or by phone (706-583-8096).

Deer Tolerant Ornamental Plants
Center Publication Number: 199

Armadillos, Georgia’s only Shelled Mammal

Source(s): Michael T. Mengak

Armadillos in Georgia

Scientists classify armadillos with anteaters and sloths. They have poorly developed teeth and limited mobility. In fact, armadillos have small, peg-like teeth that are useful for grinding their food but of little value for capturing prey. No other mammal in Georgia has bony skin plates or a “shell,” which makes the armadillo easy to identify. Just like a turtle, the shell is called a carapace.

Georgia Armadillos

Armadillos are common in central and southern Georgia and are moving northward. Only one species of armadillo lives in Georgia and the southeastern United States, but 20 recognized species are found throughout Central and South America. These include the giant armadillo, which can weigh up to 130 pounds, and the pink fairy armadillo, which weighs less than 4 ounces. About two million years ago a relative of the armadillo as large as a rhinoceros lived in South America, and small cousins lived as far north as Canada. These disappeared in the ice ages long before humans inhabited North America.


Order Xenarthra – Armadillos, Anteaters, and Sloths
Family Dasypodidae – Armadillo
Nine-banded Armadillo – Dasypus novemcinctus

The genus name, Dasypus, is thought to be derived from a Greek word for hare or rabbit. The armadillo is so named because the Aztec word for armadillo meant turtle-rabbit. The species name, novemcinctus, refers to the nine movable bands on the middle portion of their shell or carapace. Their common name, armadillo, is derived from a Spanish word meaning “little armored one.”


Armadillos are considered both an exotic species and a pest. Georgia law prohibits keeping armadillos in captivity, however. Because they are not protected in Georgia, they can be hunted or trapped throughout the year. There are no specific threats to their survival. Armadillos have few natural predators. Many are killed while trying to cross roads or highways or when feeding along roadsides.


The nine-banded armadillo is about the size of an opossum or large house cat. They are 24 to 32 inches long of which 9½ to 14½ inches is tail. The larger adult males weigh between 12 and 17 pounds whereas the smaller females weigh between 8 and 13 pounds. They are brown to yellow-brown and have a few sparse hairs on their bellies. Long claws make them proficient diggers. They have 4 toes on each front foot and 5 on each back foot. The toes are spread so that a walking track looks somewhat like an opossum or raccoon. The ears are about an 1½ inches long and the snout is pig-like.


About two million years age, a relative of the armadillo as large as a rhinoceros lived in South America. Smaller cousins lived as far north as Canada. All of these forms disappeared in the ice ages long before humans inhabited North America. At the start of the 20th century, the nine-banded armadillo was present in Texas. By the 1930s, they were in Louisiana and by 1954 they had crossed the Mississippi River heading east. In the 1950s, they were introduced into Florida and began heading north. Today, some maps (Georgia Wildlife Web: http://museum.nhm.uga.edu/gawildlife/ gaww.html) show them to be restricted to South Georgia but, in fact, they are present as far north as Athens and Rome, Georgia. They occur throughout the South from Texas, Oklahoma and Kansas through Missouri, eastern Tennessee and into South Carolina. They are currently absent from North Carolina but are likely to continue to move northward along the coast and into the Piedmont. Because they do not tolerate cold temperatures (below about 36 degrees F), several studies suggest that farther northward migration into the Appalachian Mountains will be limited.

Form and Function

The armadillo’s appearance is unique among Georgia’s mammals. The shell (carapace) is made up of scutes or bony plates attached to a tough epidermal skin layer. Since each scute overlaps slightly with the one before it, the entire shell appears to move like a telescope or accordion. The ears, underbelly and parts of the head and limbs are not covered by the shell. The head is relatively small. The skull is tubular; the lower jaw is long and slender. There are 7 or 8 teeth in each jawbone or 14-16 teeth in the lower jaw and the same number in the upper jaw. The teeth are small pegs with a single root. Armadillos can have 7-10 bands on the shell even though their name indicates nine. Males are about 25 percent heavier than females on average. Though males lack a scrotum and external testes, the sexes are easy to distinguish by the presence of four teats in females. Both sexes possess anal glands that protrude when the animal is excited. The anal glands produce a strong odor but, unlike a skunk, they do not spray.


Armadillos dig their own burrows or use the burrow of another armadillo, tortoises or natural holes. They do not hibernate but neither can they tolerate high temperature (above about 85 degrees F). During the winter months they often are active during the warmer part of the day. During the hot summer, activity shifts to the cooler night hours. While they can remain in their burrows for several days, they do not store food or accumulate large stores of body fat, so they must eventually emerge to forage. In bad weather, they can freeze to death or starve if they are unable to locate food. Armadillos rely on a good sense of smell to locate food but have poor eyesight. They eat insects and surrounding soil and plant litter while foraging, so their droppings consist of undigested insect parts, soil and litter fragments. Droppings are about the size and shape of marbles.


Armadillos reach sexual maturity at about one year of age. They breed between June and August. They have delayed implantation (a step in development when the fetus attaches to the wall of the uterus), which can last for up to four months. Implantation occurs around November and gestation lasts about four months. Generally, the female produces only one litter per year. A single fertilized egg gives rise to four separate embryos. Thus each litter consists of four identical quadruplets. Fully formed young are born with their eyes open in March or April. They weigh 3-4 ounces at birth and can walk within a few hours but remain in the nest or burrow for 2-3 weeks. Then the young follow their mother while foraging. The young leave the nest at 20- 22 days (around the first or second week of June in south Georgia), drink water at 21-25 days, eat solid food at 35-42 days, eat insects at 71-74 days, and are weaned at 90-140 days. The armor plates on the young are soft and flexible at birth — not hardening to the typical adult form until July in south Georgia. The male plays no role in raising or caring for the young.


Armadillos are largely insectivores but may consume fruit when available. Their skull, jaw and teeth are adapted to a specialized diet. Their tongue is sticky with rear facing hooks giving the tongue a rough texture. The armadillo’s diet consists mainly of invertebrates including insects (beetles, wasps, moth larvae) and also ants, millipedes, centipedes, snails, leeches, and earthworms. The exact composition varies by season, availability and geographic locations. Studies show they also consume fruit, seeds and other vegetable matter. They have been reported to consume newborn rabbits and at least one robin. It is unknown if they merely found these animals dead or not. Other items known to be consumed by armadillo include salamanders, toads, frogs, lizards, skinks, and small snakes.

University of Georgia researchers studying armadillos on Cumberland Island found that, although their diets varied seasonally, 99 percent of their diet consisted of beetle (Coleoptera) larvae, and ant and wasp (Hymenoptera) eggs, pupae and adults. White grubs and wireworms were the most frequently consumed larvae throughout the year. Armadillos were also found to consume earthworms, crabs, crayfish, butterfly and moth larvae, fruits and vertebrates. In addition, 60 out of 171 armadillo (35%) in the sample ate fruit. Grapes, saw palmetto, greenbrier and Carolina laurel cherry were most common in the diet. Armadillos also occasionally consumed spadefoot toad, five-lined skink, green anole, eastern fence lizard, rough green snake, and various snake and lizard eggs. Using remote cameras to study nest predation, several studies have shown that armadillos consume quail eggs. Other observers report that sea turtle eggs are eaten.

Feeding activity, such as digging, is often considered a nuisance, although consumption of ants, including fire ants, and white grubs may be beneficial in other ways. Small invertebrates are swallowed whole while large items are chewed. They will hold and tear apart larger food items with their claws and feet. In one study in Alabama, nearly every fire ant mound on the study site showed evidence of disturbance by armadillo. They seem undeterred by the bite of the fire ant. Armadillos have been observed tearing the bark from fallen trees, presumably to feed on the insects (beetles and termites) in the decaying wood. They move slowly while feeding and locate food items by smell. The diet shifts to fruits in the summer and fall as these items are often abundant in southern U.S. forests.


Armadillos spend most of their active time outside the burrow feeding. They move slowly – traveling between 0.15 and 0.65 miles per hour — often in an erratic, wandering pattern. Often grunting like pigs and with their snouts to the ground, they forage by smell and possibly sound. They often use their sticky tongue to probe holes searching for food, but they are also powerful diggers. Foraging pits are up to 5 inches deep and are often found in moist soil. Periodically they will stop foraging, stand upright on their hind legs balancing with their tails, and sniff the air. They also take low hanging fruits from this posture.

Armadillos mark their territory with secretions from the anal gland. Individuals may be able to recognize others through scent marking. When alarmed they can run quickly. They have a habit of leaping vertically like a bucking horse before running away in a surprising burst of speed. The anal gland’s strong odor and the sudden leaping motion may momentarily startle a predator, possibly allowing the armadillo to escape.

Contrary to popular folklore, the nine-banded armadillo cannot curl into a ball to protect itself. Armadillos are good climbers and readily climb fences although they are not known to climb trees. They often use fallen and leaning logs and trees to escape rising water along streams and rivers. Armadillos can cross water by either swimming in a typical, dog-paddle motion or walking on the bottom while holding their breath. Buoyancy is increased by ingesting air into the stomach and intestines. Armadillos can cross small water bodies by holding their breath and walking underwater for short distances. One armadillo swam across a river 140 yards wide. Having a specific gravity of 1.06 helps, since it makes them heavier than water. Armadillo are known to take mud baths on hot days, perhaps to remove parasites or to coat themselves in cooling mud.

They make a variety of low grunting sounds when feeding or to call young to mother. Other sounds are described as “wheezy grunt,” “pig-like sound,” “buzzing noise” and a “weak purring” made by very young armadillo while attempting to nurse. They are capable of learning simple tasks in a laboratory, such as recognizing patterns in a Y-maze. They are primarily solitary animals except during brief periods for mating and mother-young groups.


Armadillos prefer habitat near streams but avoid excessively wet or dry extremes. Soil type is important due to their burrowing. They prefer sandy or clay soils. Armadillos can be found in pine forests, hardwood woodlands, grass prairies, salt marsh and coastal dunes. Human created habitats such as pasture, cemeteries, parks, golf courses, plant nurseries and crop lands also provide suitable habitat. They also forage along roadsides. While foraging, armadillos always seem to know where they are and, if alarmed, often take a direct route to the safety of a nearby burrow or tangle of roots and briars. They usually dig their own burrows. Burrow entrances will be 8 to 10 inches across and range from 2 to 24 feet long averaging 3 to 4 feet. The burrow entrance is often concealed among clumps of vegetation, fallen logs or under buildings. Each armadillo may have 5 to 10 burrows. The average number of different burrows used per individual armadillo was 10.9. Other animals will use armadillo burrows including rabbits, opossums, mink, cotton rats, striped skunks, burrowing owls, and the eastern indigo snake.

Occasionally, armadillos will cohabit with other animals. Armadillo do not always dig a burrow; some will build nests out of dry grass. These nests resemble small haystacks and are often used in areas of wet soil. On Cumberland Island, University of Georgia researchers found that 75 per-cent of all dens were under saw palmetto plants. An individual’s home range varies from 1.5 to 22.5 acres. The home range size is smaller for the armadillo than for similar sized animals. Researchers at the University of Georgia found that armadillos on Cumberland Island had a home range of 13 acres in summer and only 4 acres in winter. Armadillos spent 65 percent of their time in burrows in winter compared to only 29 percent in summer.


Armadillos have few wild predators, but coyotes, dogs, black bears, bobcats, cougars, foxes and raccoons are reported to catch and kill armadillos in places where these predators occur. Hawks, owls and feral pigs may prey on armadillo young. One study noted a decline in armadillo numbers as feral pig populations increased. Humans and highways are significant sources of mortality in many areas. One study in Florida, however, found no juveniles in a road-killed sample.


The sex ratio by litter is 1 male litter (= 4 identical quadruplets) per 0.78 female litters in Florida. Armadillos probably live 6 to 7 years in the wild. Population density is about one animal per 4 acres but could range as high as two animals per acre.


Their flesh is tasty and often eaten by people. Weather, especially cold winters, may be the most effective barrier to northern range expansion. Their normal body temperature is 92-95 degrees F.


Armadillos may carry diseases transmissible to humans, but reports are rare. Armadillos can acquire leprosy and are used in medical research to study this disease. Only two cases are known in which a human contracted leprosy from wild armadillos. Both cases are from Texas, and the transmission occurred by consuming raw or undercooked armadillo meat. There are no reported positive cases in Georgia, Alabama or Florida. One wild armadillo in Texas was reported to have rabies but no known transmission to humans has occurred. Armadillos on Cumberland Island, Georgia, had between 0 and 3 species of parasitic worms per individual. The average was 14 worms per individual armadillo but the impact of these parasites on the health of the animal is unknown.

Economic Value

One study in Texas from 1975-1979 put the total amount of damage at $20,000 for a limited area but did not specify the type of damage. In Georgia, 78 percent of county agents reported receiving requests for information regarding armadillos, and that armadillo complaints accounted for nearly 11 percent of all animal complaints they received each year. No dollar value was attached to the damage complaints, however. Furthermore, the monetary value of damage done to vehicles is not known.

Damage occurs to lawns and landscape due to digging for insects and other food items. Shallow holes 1 to 3 inches deep and 3 to 5 inches wide, usually shaped like an inverted cone, are the most common landowner complaints. Armadillos can uproot flowers and other plantings through their foraging. Damage is generally local and of a nuisance variety more than a large scale economic loss.

Legal Aspects

Armadillos are not protected in Georgia. There are no season or harvest restrictions.

Control to Reduce

Armadillo can be controlled by trapping. Wire cage live traps measuring at least 10 x 12 x 32 inches are recommended. Use of wings, constructed of 1 x 6 inch lumber in various lengths and placed in a V-arrangement in front of the trap can help to “funnel” the armadillo into the trap. Setting traps along natural barriers like logs or the side of a building increases capture success. Placing the trap in front of a burrow entrance is better than random placement in the environment. No bait, lure or attractant has been shown to be effective in increasing capture success, although there are numerous report of baits used with varying success. No repellents are registered for use with armadillo. No toxicants (poisons) are registered for use. Pesticide use to reduce insect populations in landscape settings may be effective. No fumigants are registered for use to control armadillo. Shooting is an effective control technique. Use a .22 caliber rifle in a safe and legal manner. Check city and county ordinances before discharging weapons. Always practice safe gun handling procedures.

Management to Enhance

Management activities are usually directed at control and elimination rather than enhancement.

Human Use

Native American Use – None. Armadillos are widely used (and considered a delicacy) by many cultures in Central and South America. Colonists View – None.

Center Publication Number: 196