Armadillos in Missouri:
Techniques to Prevent and Control Damage
Robert A. Pierce II
Extension Wildlife Specialist
Department of Fisheries and Wildlife Sciences
Armadillos are becoming more common in portions of Missouri, particularly
in the southern and central regions of the state. Their range has been expanding
in the United States since the 1850s when the armadillo moved into Texas from
Mexico. Originally the species was only found in South and Central America.
As populations continue to expand, the possibility of encounters with humans
will increase. This publication is designed to provide general information on
armadillos, their damage and their control.
Identification
The nine-banded armadillo (Dasypus novemcintus) takes its name from the nine
moveable rings of armor between its shoulder and its hip shields. Its long tail
is also protected by rings of armor. Armadillo tracks are identified by three
toe prints and sharp claw marks. Armadillos are about the size of opossums.
Biology and behavior
An understanding of the life history and habits of armadillos is helpful
in developing an effective control program. Armadillos are mainly nocturnal,
which means they are active at night. However, they occasionally move about during
the day. They burrow in the ground and have extremely strong legs that are adapted
for digging. They often root about in ground litter searching for insects, grubs
and other invertebrates. Armadillos have poor eyesight and depend on their sense
of smell to locate prey underneath the soil.
With their sticky tongues, armadillos capture insect prey and swallow them
whole. Lacking front teeth, armadillos will chew larger prey with the help of
peglike molars.
While searching for food, they seem oblivious to anything else and may come
in close contact to humans before becoming alarmed. When startled, they jump
in the air (which greatly reduces their chances of surviving an encounter with
a vehicle). Armadillos make a great deal of noise while traveling through the
woods. In fact, deer hunters in the Ozarks are often surprised that the trophy
buck they heard was actually an armadillo searching for food. Armadillos can
run well and are good swimmers.
A female produces only one litter each year, usually in March or April, after
a 150-day gestation period. Armadillos are unique in that they give birth to
four young, all of the same sex. Inside the female, one egg becomes fertilized.
This egg then divides into four eggs, each one exactly the same as the first.
These eggs grow into four identical young that resemble miniature adults. They
are the only mammal in Missouri that reproduces in this manner.
Armadillos do not tolerate freezing temperatures, and this fact has largely
prevented them from moving farther north. As winter arrives, their food supply
becomes scarce and frozen ground conditions prevent them from digging in search
of food. To escape the cold, armadillos will retreat underground. However, they
are unable to hibernate and will either freeze or starve to death in these conditions.
Armadillos will usually dig a burrow 7 or 8 inches in diameter and up to
15 feet in length for shelter and for raising young. Burrows are often located
in rock piles, around stumps and brush piles, and in dense woodlands. They may
often have several den locations in an area to use for escape.
Potential for damage
Most armadillo damage occurs as a result of their rooting in lawns, golf
courses, vegetable gardens and flower beds. As they search for food, they dig
shallow holes in the ground. Characteristic signs of armadillo activity are shallow
holes, 1 to 3 inches deep and 3 to 5 inches wide. They will also uproot flowers
and other vegetation while searching for food. Some damage is caused when they
burrow under foundations, driveways, and other structures.
Armadillos have been known to carry the bacterium associated with human leprosy
(Mycobacterium leprae), but there has been no conclusive evidence that humans
can contract leprosy from contact with armadillos. The Field Manual of Wildlife
Diseases in the Southeastern United States summarizes what is known about the
link between armadillos and leprosy:
- Whether humans can contract infection (leprosy) from armadillos is debatable,
although case histories suggest that a few occurrences of leprosy among armadillo
handlers in Texas may have been acquired during many years of catching, handling,
skinning, and eating armadillos. A widely accepted hypothesis is that the organism
exists in the soil in certain regions, especially Louisiana and coastal Texas,
and that both armadillos and humans contract infection from this environmental
source.
Damage prevention and control
Damage caused by armadillos is usually localized and is most often a nuisance
rather than an economic loss. However, if a damage control program is warranted,
here are a few techniques that may be helpful:
Exclusion
Armadillos can climb as well as burrow. Fencing or other barriers may exclude
them under certain conditions. A fence slanted outward at an angle, with a portion
buried in the ground, can be effective.
Habitat modification
Because armadillos feed on invertebrates in the ground, eliminating the food
source will often cause them to look elsewhere for food. However, ridding the
soil and vegetation of all insects, worms and grubs is not practical and may
be detrimental to the plants and other life forms in the area.
Removing debris and brushy areas from around your home may discourage armadillos.
However, brushy areas are often valuable habitats for songbirds and other wildlife.
Damage is often localized to a particular area. If the damage is isolated
to a garden area, an electric fence can be an effective form of control. A single
strand 3 to 4 inches off the ground should be sufficient. However, be careful
when placing an electric fence in areas where children play.
Trapping
Figure 2
Live traps can be effective in catching armadillos, especially if
boards are placed at the opening to direct the animals into the trap.
Armadillos can be captured in 10 x 10 x 32-inch live or box traps, such as
Havahart, Tomahawk or homemade types. The best locations to set traps are along
pathways to their burrows and along fences or other barriers where the animals
may travel.
The best trap is one that can be opened at both ends. Its effectiveness is
improved by using "wings" of 1 x 4-inch or 1 x 6-inch boards about 6 feet
long to funnel the animal into the trap (Figure 2). This set does not need baiting.
If bait is desired, use overripe or spoiled fruit. Other baits that may be effective
are fetid meats or mealworms.
Shooting
Spotlighting and shooting armadillos at night is an effective and selective
method of control. However, this method requires constant vigilance to find the
animal. In addition, local regulations on discharging firearms may prohibit this
control method.
Toxicants and repellants
No toxicant or repellent is currently registered or known to be effective
for armadillo control. Although certain fumigants may be effective, none are
currently registered for controlling armadillos.
This publication has been adapted from ANR-773 Controlling Armadillo Damage
in Alabama, published by the Alabama Cooperative Extension System.
Brand names appearing in this publication are for identification purposes
only. No endorsement is intended or implied.
G9456, new March 2007