Why do three-banded armadillos roll into balls?

Answer: Armor protects from predators

Armor protects from predators ✓ — Correct! When frightened, a three-banded armadillo tucks its head, legs and tail inside its hard shell so that only the armor shows. The soft, hairy belly stays hidden, and the shell can even snap shut on a predator's paw. This works against most natural predators, though it makes them easy for poachers to pick up.

Conserves body heat in cold — Wrong. Rolling into a ball is a response to danger, not to cold. Armadillos deal with chilly weather by staying in their burrows or becoming less active, not by curling up to trap warmth.

Catches insects while rolling — Wrong. Armadillos find food by digging with their strong claws and sniffing out insects, not by rolling. The ball shape is purely defensive, triggered when they feel threatened.