Over the course of the four-year study, 15 (out of 835) unpainted and four (out of 543) cross-painted cattle were killed by lions; none of the 683 cattle with painted eyes were killed.

Between 2015 and 2018, the team stamped eyes with acrylic paint to the behinds of 683 cattle, drew black crosses on 543 cattle and left the butts of 835 others alone, according to the study.

What do you get when you paint a pair of eyes on a cow’s butt? The answer: a cost-effective approach to scaring predators away. The promise of this simple trick, called the “i-cow” solution, has been ...