How et al, Zebra stripes, tabanid biting flies and the aperture effect]Various ideas have been tossed around in the last 150 years about the African equids’ stripes. They covered the horses with rugs featuring an array of designs: from single-color black or grey to checked patterns and, of course, zebra stripes. The flies made successful landings much less frequently on the horses in stripes than on the solids. “Once we’d lost the aperture effect as a possible explanation for how zebra stripes affect fly behaviour, we then had to turn to other suggestions. So there might be some other kind of illusion that is happening in the eyes of these flies.