How to Clean a Hippopotamus , a book about animal symbiosis, offers readers a close-up, step-by-step view of nature’s fascinating partnerships. Find out why a mongoose comes running when a warthog lies down, how a crab and an iguana help each other out, why ravens follow wolves, and more. Witness the ingenious lifestyles of some of the world’s most unusual animal partners in this book of curious biology, a symbiotic collaboration by Steve Jenkins and Robin Page.