Far from being an abnormal or infrequent activity, cannibalism is a naturally occurring behavior with far-reaching implications for the ecology, life history, and evolution of many species. This book offers the first detailed review of the subject, covering the contextual and taxonomic diversity of cannibalism, and explaining its costs, benefits and taxonomic consequences for a broad distribution of species from lower eukaryotes to higher primates. The authors explore the different varieties of cannibalism, including infanticide, mating and courtship rituals, gerontophagy, oophagy, and competitive interactions. They also assess the ecological and evolutionary causes and effects of cannibalistic behavior, using the theoretical tools successfully applied to the study of foraging behavior, sociality, demography, and genetics. These findings will interest a broad audience of ecologists, evolutionary biologists, and students of animal behavior.