Book excerpt: This work presents a natural history of the Cottonmouth Moccasin, a species of crotaline snake. The writer aimed to help people learn about its economic importance, determine what factors limit its geographic distribution, define the role of the cottonmouth in its ecological community, and compare the cottonmouth's life history with that of other crotalid snakes. Contents include: Introduction Acknowledgments Systematic Relationships and Distribution Description Habitat and Limiting Factors Reproduction Growth and Development Shedding Food Habits Mortality Factors Behavior The Venom The Bite Summary