The word armadillo is Spanish for "little armored one." This midsize mammal that looks like a walking tank is a source of fascination for many people but a mystery to almost all. Dating back at least eleven million years, the nocturnal, burrowing insectivore was for centuries mistaken for a cross between a hedgehog and a turtle, but it actually belongs to the mammalian superorder Xenarthra that includes sloths and anteaters. Biologists W...