Newswise — As sure a sign of summer as lightning bugs but maybe not as welcome, gnats are often thought of as no more than flying specks and a nuisance. But as this Smithsonian Snapshot shows, magnified under a microscope their appearance reveals that they are “true” flies, meaning they have only two wings instead of four.

It is no coincidence that these tiny pests swarm around people’s faces and often end up in their eyes. These non-biting flies, no bigger than a few grains of salt, are attracted to fluids secreted by your eyes—in fact, they are also known as “eye gnats” or “eye flies.”

There are hundreds of gnat species worldwide, but Liohippelates pusio (pictured here) is one of the more common ones in the U.S., especially in the southeastern states where there is loose sandy soil for the gnats to lay their eggs in. And while a gnat’s life cycle can be as short as 11 days, that does not guarantee relief from these persistent pests—they can have multiple generations in one season.

Register for reporter access to contact details