The zebra’s stripes were long explained as camouflage, or as a way of dazzling a lion. In 2019 Tim Caro and his colleagues filmed horse flies around zebras and plain horses and found that, from a distance, the flies treated them the same: they circled and came in at about the same rate. The difference was in the last moment. Over a horse a fly slowed down and landed. Over a zebra it kept its speed, failed to brake, and bumped off. Then the team put striped cloth coats on horses. Far fewer flies landed on the coats, while the horses’ uncovered heads were attacked as often as before. So the stripes don’t hide anything. The fly sees the animal perfectly well and wants it. What the stripes take away is the part where you have to judge exactly how close you are.