The book examines the entire range of animal movements. Beginning with humans and other complex animals and ending with single-celled organisms, the book describes and illustrates how animals walk, run and jump; crawl and climb; soar and fly; float and swim. Are insects crawling on the underside of leaves defying gravity? Are fleas really nature's premier jumpers? Can a running cheetah reach 70 miles per hour? Do flying squirrels and lizards actually fly? The answers to these and other related questions are in this volume. The range and speed of movement in all complex animals are governed by muscles. This book begins with an overview of muscle physiology that explains the relation between energy costs and the ability to do work and exert force. Subsequent chapters examine in detail the specific ways animals travel, as the author demonstrates how body structure and patterns of movement are adapted to produce the most energy-efficient performance possible. The book offers dozens of examples of animals in motion, describing experiments that reveal among other things-how human walking differs from all other forms of animal walking; how insects adhere to surfaces; how the flight of birds is analogous to that of helicopters rather than airplanes; how ducks, penguins, squid, dolphins, trout, and eels exemplify different forms of swimming; and how amoebas "walk" by extending their pseudopods.