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. J. Loughry and Colleen M. McDonough have studied the nine-banded armadillo (Dasypus novemcinctus) for more than twenty years. Their richly illustrated book offers the first comprehensive review of everything scientists know about this unique animal. Engaging both scientists and a broader public, Loughry and McDonough describe the armadillo’s anatomy and physiology and all aspects of its ecology, behavior, and evolution. They also compare the nine-banded armadillo with twenty or so other, related species. The authors pay special attention to three key features of armadillo biology—reproduction, disease, and habitat expansion—and why they matter. Armadillos reproduce in a unique and puzzling manner: females always give birth to litters of genetically identical quadruplets, a strategy not found in any other vertebrates. Nine-banded armadillos are also the only vertebrates except for humans known to contract leprosy naturally. And what about habitat expansion? The authors suggest that the armadillo’s remarkable spread across the southeastern United States may be the consequence of its most notable feature: a tough, protective carapace. Biologists, evolutionists, students, and all those interested in this curious creature will find The Nine-Banded Armadillo rich in information and insight. This comprehensive analysis will stand as the definitive scientific reference for years to come and a source of pleasure for the general public.