Why are humans and other mammals covered in hair, and why are there so many different types of it? Vivid photographs paired with a duo of quirky, illustrated hair guides serve to illuminate the fascinating facts about mammal hair: why it exists, what it's good for, and more. Readers will learn about different types of animal coats, such as fur and down, and explore the many different forms guard hairs take, such as the quills on a porcupine.