The Southern Three-banded armadillo is 8.5 to 11 inches long not including the tail which adds another 2-3 inches. The rough, thick and heavily armored shell or carapace accounts for only 16% of the body weight. The animal has two large shells, front and back, with two to four moveable bands in between. The Southern Three-banded armadillo is one of two species that can curl into a ball and completely enclose their bodies into protective shells about the size of a large grapefruit. While predators cannot open them, man can easily pick them up. Apparently this species does not dig holes, but utilizes the abandoned burrows of anteaters.
They run rapidly, with a peculiar gait with only the tips of their foreclaws touching the ground. They are diurnal and run through the grass with their backs arched, sniffing and scraping as they go. They are rather noisy, making hissing and breathing sounds.