The animal known for its spiny back and ability to roll into a ball is the armadillo. This unique mammal, native to the Americas, has a hard shell made of bony plates covered in skin, which provides protection against predators. When threatened, an armadillo can curl into a tight ball, using its armor to shield itself from danger. Armadillos are primarily nocturnal and have a diet that consists mainly of insects, grubs, and small invertebrates. They play an important ecological role by aerating the soil and controlling insect populations in their habitats, which range from forests to grasslands.