It has been reported to occur primarily in unbroken, relatively undisturbed forest and usually near water. Nearly half of these burrows were located in active termite mounds. The average distance to the woods for burrows located in grassland or brushland was 192 meters. Burrows averaged 41 cm in width and 31 cm in height. Burrows of different ages were found in close proximity, indicating that Priodontes reuses certain areas.
Activity is strictly nocturnal.
Despite its rigid appearance, the giant armadillo is fairly agile and often balances itself on its hind legs and tail, with the forefeet off the ground. It also digs extensively to obtain food. The diet consists primarily of termites, but ants, other insects, spiders, worms, larvae, snakes, and carrion are also consumed. Priodontes frequently is accused of eating garden vegetables, but it probably digs in gardens to find insects and not for the vegetables. They weigh up to 113 grams each and have tough, leathery skin.