The Moiré Trap for Horseflies
A zebra grazes in the African savanna, surrounded by a cloud of flies — horseflies, tsetse flies, and mosquitoes. But instead of landing calmly, the insects jerk, miss their target, and crash into the hide. The reason is not camouflage but the structure of the fly's eye.
The horsefly's eye is a mosaic of thousands of tiny tubes, ommatidia, each pointing in a different direction.