A BALL OF ARMOR

The Denver Zoo is home to Willow and Chaco, three-banded armadillos - and they can teach Broncos a thing or two about defense. "Three-banded armadillos are the only armadillo species that can roll up into a complete ball, tucking in their head, tail, and legs to create a perfect armored sphere!" the zoo says. "This clever defense keeps them safe from predators in the wild." The zoo is also home to Dillon, a nine-banded armadillo. [Photo: Denver Zoo]