The dictionary definition of a mammal says that mammals give birth to live young, but that's not always true. Echidnas and platypuses, while still technically mammals, lay eggs. Why they do so is one of the strangest adaptations of mammals on Earth. Readers explore this and many other incredible and bizarre adaptations of all kinds of mammals, including the purpose of milk teeth and the hairy truth about camouflage and the coats of many animals. Full-color photographs showcase each adaptation for curious readers as they absorb information about life cycles, predator-prey relationships, and more from the main content.