Researchers put a horse in a zebra costume for science

If you ever learned anything about zebras growing up, the key fact about their stripes you might believe is accurate might not be accurate at all. That factoid would be that the stripes on a zebra are to help camouflage the animals inside the herd, so predators have a harder time catching a meal. Scientists from the University of California and the University of Bristol have conducted a series of experiments to figure out why the stripes of a zebra foil biting flies.

It's warding off these biting insects that the stripes are for according to the scientists. The experiments were conducted to better understand how the stripes manipulate the behavior of biting flies as they attempt to land on the animal. The experiments were conducted on a horse farm in Great Britain and involved a horse wearing a zebra costume and actual zebras.

The team closely observed zebras as flies attempted to land on them and made detailed videos to record flight trajectories as flies move close to the zebras. The team dressed the horses and zebras sequentially in black, white, and then black and white striped coats. The study found that flies were as attracted to zebras as they were to horses indicating the stripes do nothing to deter flies at a distance.

However, once the flies are close to the zebras, they tend to fly past the zebra or bump into it, that indicates the stripes might disrupt the flies' ability to control the landing. The team found that compared to the rate that flies landed on the white and black coats, they hardly ever land on the striped coats.

The assumption is that the stripes somehow "dazzle flies" when they are close enough to see the stripes with low-resolution eyes. Researchers also found that horses and zebras react differently to flies. The zebra swished tails almost continuously to ward off flies, while horses primarily twitch and occasionally swish tails to ward off flies. The zebra tail swishing, and at times running, means flies that land on zebras are tossed off more quickly.