from this morning's Num Lock News

In Botswana, farmers don't like it when lions kill their cattle, and can retributively hunt the big cats. Conservationists wanted to diffuse this situation — keep the cattle alive and keep the lions alive — and a new study details a low-tech, highly successful strategy to ward off predators, namely by stenciling eyes on the butts of cows. The study painted 14 herds with 2,061 head of cattle with either a set of eyes on the backs of cows, a set of crosses, or nothing at all. Of 835 unpainted cows, 15 were killed by lions over the course of four years, of 543 cross-painted cows just four were killed, and none of the 683 cows with eyes on their butts were killed.

Jennifer Ouellette, Ars Technica