Did you know that domesticated sheep need seven de-worming treatments a year, while their wild cousins are lean, muscled and rarely get worms?
According to scientist Cindy Engel, that's because animals in the wild have an innate ability to keep themselves healthy. But not all animals are so fit - elephants are inclined to get drunk on fermented fruit when they get stressed out.
Jenni explores with Cindy Engel the strange world of animal self-medication and finds out how the path to good health may lie in animal self-help. Wild Health by Cindy Engel, Weidenfeld and Nicolson; £20