For years, theories ranged from camouflage against predators, confusing lions during a chase, regulating body temperature, or even serving as a social signal among herd members. But studies comparing zebra stripe patterns across Africa with environmental factors have revealed a surprising frontrunner: stripes help keep biting flies at bay.

Horseflies and tsetse flies — which carry diseases — are far less likely to land on striped surfaces. The alternating black and white patterns seem to confuse the insects’ vision and disrupt their ability to make a clean landing. Experiments with striped coats placed on horses showed far fewer fly landings compared to solid-colored coats.

This doesn’t mean the other theories are completely wrong — stripes may also provide some temperature regulation and social recognition benefits — but the anti-fly defense is now considered the most convincing primary explanation.

So, in short: zebras aren’t wearing nature’s barcode for camouflage alone — they’re rocking an insect-repelling suit of armor.