Being hairy may be more advantageous than originally thought. When it comes to blood-sucking parasites, the fine hair that covers our body helps us detect the presence of insects on our skin. It also acts as a barrier, helping to prevent bug bites, according to a study published in the U.K. journal Biology Letters.

Researchers at the University of Sheffield placed hungry bedbugs on the arms of 29 volunteers. One arm of each subject was shaved.

They found that not only do the hairs help us feel the bugs on our skin, but the hairs increase the amount of time before a parasite can find a suitable site to start sucking blood.

The findings may explain why we lost the thick coat of hair of primates, but kept some body hair, says coauthor Michael Siva-Jothy of the university´s Department of Animal and Plant Sciences.

“Our proposal is that we retain the fine covering because it aids detection and if we lost all hair, even the relatively invisible fine hair, our detection ability goes right down,” he said.