A team of researchers at UC Davis have answered that age old question -- why do zebras have stripes?

Camouflage, heat management, a social function -- all possible reasons why zebras have stripes.

But the researchers at UC Davis took one proposed theory and put it to the test Do stripes help ward off biting flies?

"It really was a sort of slam dunk for this idea that biting flies are the evolutionary force driving the stripes," Tim Caro, a UC Davis professor of wildlife biology said. 

Caro says they mapped out areas of the world where zebras evolved, and the biting flies native to those areas.

"To my amazement, again and again, it's biting flies that overlapped equids that are heavily striped," he said. 

Caro says the short hair of the zebra may leave them more exposed than other mammals to biting flies.

And he says he'd like to see more research on why biting flies tend to avoid striped surfaces. 

Listen to Professor Tim Caro's complete interview with KFBK here: