When the researchers put various colored cloth coats on horses, the zebra-patterned coat led to a drastic drop in how many flies they saw landing on a horse's covered body. Below, the vertical axis measures the average number of fly landings observed per half hour. But horses wearing the zebra-striped coat had about the same number of flies land on their uncovered heads as those in solid white or black coats. Flies seem to stay away from stripes, but stripes at a distance don't protect the horses.
