Contrary to popular belief, not all armadillos can roll into a ball for self-defence. The southern three-banded armadillo is one of only two species that can do so. When startled, it closes its shell completely around its body, leaving a small gap that it squeezes shut on the nose or paw of a would-be predator.
The hard shell covering the tail, top of head and outer surfaces of the limbs is made up of bony plates, called scutes. Unlike in other armadillo species, these plates are not attached to the skin on the sides, allowing the head, legs and tail to be tucked in like pieces of a jigsaw.