Wildlife: March 2000

We receive numerous calls every year from homeowners and other turf managers regarding armadillo damage to their landscape. Before discussing damage management methods, I want to discuss some basic biology of this curious animal.

Although generally considered a recent invader, armadillos were found as far north as Rogers County, Oklahoma, in the 1930s. They reach a mature weight of 8 to 17 pounds. Tracks indicate four toes on each front foot and five on the hind feet. Females produce a litter, most commonly four, of monosex siblings in March or April. Young are weaned in three months.

Armadillos forage by probing leaf litter and the soil surface with their snout to locate prey. The majority of their diet includes invertebrates (beetles, ants, termites, millipedes, roaches, crickets, grasshoppers, earthworms, snails, slugs, larvae, etc.) that live in soil, leaf litter, and rotten wood. Minor food items include lizards, small snakes, salamanders, eggs, mushrooms and other fungi, and fruits (grape, mulberry, plum, persimmon, juniper, etc.). The distribution of armadillos in southern Kansas and Missouri probably represents their northern limit because of their difficulty in foraging on frozen ground.

Home ranges for adults reportedly vary from 8 to 27 acres. 'Dillos usually dig several dens, up to 15 feet long, within their home range. At least one den has a nest chamber, usually lined with vegetation. Entrances to adults' tunnels are about 7 inches in diameter. Armadillos are generally nocturnal during hot weather but diurnal (active during the day) in cold weather.

Predators include dogs, coyotes, and bobcats, but automobiles kill many armadillos. Their ability to harbor the human leprosy bacterium has made them important biomedical research animals.

Armadillos damage peanut, corn, and cantaloupe crops, but mostly lawns, golf courses, flower beds, and gardens by rooting in them. They characteristically dig small, shallow holes to search for food, sometimes uprooting ornamental plants. Skunks occasionally cause similar damage, which can be mistaken for that of 'dillos. Damage is most intense to landscapes irrigated during drought: the relatively soft, moist soil harbors more food than the surrounding sun-baked land.

The most direct control method is shooting, since they are not a protected species. This option may not be legal, safe, or socially acceptable in some suburban locations. During summer, nocturnal activity patterns are unpredictable, which may require all-night vigils. Various mesh-wire fencing designs can be effective, especially if they include a buried-wire portion. However, the aesthetics and cost of a fence must be weighed against the damage incurred.

Armadillos can be trapped in well-constructed box or cage traps. Those that open at both ends (double-door) work best. The use of "wings" to funnel armadillos to the trap opening is the key to success (see photo). Wings can be made of whatever is handy, including lumber (e.g., 1" x 6"), mesh wire, and plastic fencing material. Take advantage of existing barriers such as fencing, house walls, or curbing as well. Wing length is not critical, but the more travel routes excluded, the better. Traps set in this manner do not need bait. Conibear 220 traps are an effective killing trap but are illegal to use in Oklahoma. Even where their use is legal, only very experienced personnel should use them in suburban settings because of the danger to pets or small children.