This book is divided into seven chapters. The first chapter explains the world of animals: how they are classified; their behavior; where they live; and threats to their survival. The remaining chapters present the major animal groups: mammals, birds, reptiles, amphibians, fish, and invertebrates. Each chapter starts with an introduction, followed by pages that describe the main groups that belong in that chapter. Special feature pages throughout the book highlight interesting animal characteristics. A glossary and list of animal sizes can be found at the back.