Mammals take care of their young and live in groups, from a pride of lions to a passel of opossums, but even though mammals have features in common, the physical and behavioral adaptations of each species make them unique and interesting. This captivating text introduces readers to the characteristics that make an animal a mammal as well as the variations on that characteristic, such as the different kinds of body hair. Featuring color photographs and fast facts, it supports the Next Generation Science Standards core ideas through content about adaptation, ecosystems, and biodiversity. This book is an excellent addition to any animal library catering to young readers.