From furry pets to mighty wild animals, mammals are one of the most familiar and diverse groups on Earth. This book introduces readers to the key features that define mammals, including hair or fur, warm-blooded bodies, and the ability to nurse their young. Clear, accessible text explains how mammals are similar and different from one another, the basic mammal life cycle, and how mammals have adapted to varied habitats around the world. With vivid photos and engaging facts, this book helps readers explore the incredible variety of mammals and the important roles they play in nature.