For readers of Inside of a Dog and The Soul of an Octopus, a fascinating, charming, and revelatory look at the science behind why animals play that shows how life—at its most fundamental level—is playful. In Kingdom of Play, critically acclaimed science writer David Toomey takes us on a fast-paced and entertaining tour of playful animals and the scientists who study them. From octopuses on Australia’s Great Barrier Reef to meerkats in the Kalahari Desert to brown bears on Alaska’s Aleutian Islands, we follow adventurous researchers as they design and conduct experiments seeking answers to new, intriguing questions: When did play first appear in animals? How does play develop the brain, and how did it evolve? Are the songs and aerial acrobatics of birds the beginning of avian culture? Is fairness in dog play the foundation of canine ethics? And does play direct and possibly accelerate evolution? Monkeys belly-flop, dolphins tail-walk, elephants mud-slide, crows dive-bomb, and octopuses bounce balls. These activities are various, but all are play, and as Toomey explains, animal play can be seen as a distinct behavior—one that is ongoing and open-ended, purposeless and provisional—rather like natural selection. Through a close examination of both natural selection and play, Toomey argues that life itself is fundamentally playful. A globe-spanning journey and a scientific detective story filled with lively animal anecdotes, Kingdom of Play is an illuminating—and yes, playful—look at a little-known aspect of the animal kingdom.