Naturalists first observed nine-banded armadillos in the United States in 1849, in the Rio Grande Valley. Since then the peculiar mammal has expanded its range into the Southeast at a rate 10 times faster than typically seen in mammals. Although they are slow movers, average walking speed is about a third of a mile an hour, they can break into a run when startled. Armadillos are usually born in sets of four, all of the same sex. Each armadillo is a clone of its three siblings. One female can populate a new area.

Armadillos live in burrows. A single armadillo may have up to 15 burrows (each 8 inches in diameter and 2 to 25 feet long) in its 10-acre range. Some burrows have several entrances for emergency access, but there is always a main entrance which the armadillo uses most of the time.

The armadillo has a particularly interesting method for crossing water. When faced with a stream, the armadillo will simply walk across the bottom, under water. However, when up against a wider body of water, the armadillo will swallow enough air to inflate its stomach to twice its normal size. This increased buoyancy then allows the armadillo to swim across. Afterwards, it takes the armadillo several hours to release all the excess air from its body.