In Botswana, why do some farmers paint circles on the back of their cows?
And the answer: To prevent lion attacks.
Botswana has one of Africa's largest populations of lions. To prevent the big cats from attacking cattle, some farmers have begun painting eyes on their cows' backsides. The idea is that lions, who like to be stealthy, will think they've been seen, and won't want to sneak up behind the cows.
Lions are curious predators that base their hunting abilities on stalking their prey. When they think they are unseen, these massive cats will approach to within jumping distance before striking. However, once revealed, lions often abandon the pursuit of their prey and run to safety.
Livestock can be easy prey for stealthy lions. Cows, often lethargic and unassuming, are taken down by lions in large numbers in Botswana and other parts of Africa. Often the subsistence farmers will attempt to stop the lion by shooting or poisoning it. By painting "eyes" on the backside of the cows, both the lion's and cow's lives are preserved.
To learn more about the cow-stamping process, check out this BBC article.