Some armadillos can roll themselves into a complete ball for protection but the nine-banded, or long-nosed, armadillo (Dasypus novemcinctus) prefers to escape to the safety of its burrow where it wedges itself in, arching its back against the burrow walls. A master of escape, this armadillo has been known to outrun dogs despite its short legs and is adept at crossing water. Not just a good swimmer, the armadillo can run along the bottom of shallow waterways, escaping unseen.
Armadillos are unique in that their litter always includes identical quadruplets that develop from a single egg. For this reason, they are valued for medical research into multiple births. Similarly, they are used for research into leprosy as they are the only non-primate creature to suffer from this disease.