Why Do Flies Circle You?

Flies are attracted to humans because we hold the promise of a free lunch. The most likely fly you’ll encounter is the common housefly. Only a few millimeters long, black with big, red eyes, these flies are found inside and outside of your home. Houseflies are attracted primarily to stinky stuff like garbage, feces and dead things, but also like the scent of human food or even what’s in Fido’s bowl. As well as the obvious food sources, you’re covered in dead skin cells, oil and salt that are all delicious to flies. Flies will keep circling around you because to a housefly, you’re a veritable buffet.

Common houseflies aren’t the only type of fly that can become a nuisance by circling around you. Fruit flies are another common fly that are a little smaller than houseflies, with a tan or brown body. Fruit flies are attracted to rotting fruit or vegetables as well as liquor and beer. Blowflies, also called bottle flies, are larger than houseflies and are easily recognized by their metallic green or blue bodies. You can actually hear blowflies coming by the loud buzzing sound they make when they fly. Blowflies like to hang around humans because they are attracted to decaying organic material like rotting food, trash, and dead plants or animals.

You would think that because you’re constantly swatting and swinging, flies would avoid humans as giant sources of danger. However, successfully swatting a fly is incredibly difficult. Flies have complex compound eyes that allow them to see all around them. It’s almost impossible to sneak up on a fly without being seen. According to researchers at the California Institute of Technology, flies are able to fly away from danger, no matter what they’re doing, within 100 milliseconds of recognizing a threat. Flies basically have a sixth sense that allows flying away from danger lightening quick. To a fly, we aren’t much of a threat, but a clumsy smorgasbord. As long as they keep circling, they’ll get a meal in eventually.

While most flies don’t bite, they can carry disease, so it’s a good idea to try and keep them at bay. The best way to combat a fly infestation is to keep things clean. Never leave excess food in your pet food bowls when they’re through eating. Keep your sink clean of dirty dishes, and take your trash out regularly. Wipe down trash cans both inside your home and outside to keep small particles of fly-attracting yuck away. Make sure your windows and doors are sealed and flies aren’t finding their way indoors through tiny cracks. While it’s near impossible to have a completely no-fly zone, keeping clean will keep them to a minimum.