How To Keep Flies Away From Your House

There’s nothing more annoying than the persistent buzz of a fly indoors, not to mention the fact that some flies can transmit pathogens that cause serious illnesses such as food poisoning, cholera, and dysentery. Bottom line: Flies are never a good thing inside our homes.

Fortunately, out of the more than 110,000 species of flies, only a few types are common pests around the house. “The ones that cause the most problems are called filth flies. But they’re doing what they were born to do, which is to break down organic matter,” says Faith M. Oi, Ph.D., entomologist and extension professor at the University of Florida. “If we can be mindful about our behaviors, we can minimize our chances of getting sick.”

Keeping them out of our homes in the first place is the goal. “The truth is there’s no silver bullet with fly control,” says Elmer Gray, entomologist and researcher with the University of Georgia. “But we can take some basic steps to limit their access to our homes.”  

Read on to learn how to keep flies away, including the best natural ways to keep flies out of your house:

What Kind of Flies Get Indoors?

Any type of fly can make its way indoors, but the most common is house flies, which are about 1/4-inch long with four dark stripes down their middles. They lay eggs in organic matter in places such as garbage, compost, or in the thin film inside recycling bins.

In ideal conditions, flies reproduce in less than a week, says Oi. The warmer the environment, the faster they progress through the life cycle from egg to adult fly. For example, if you forget to take out the trash, and then go on vacation for a week, you could have fly larvae wiggling around in your kitchen when you return. (Yikes!)

Blow flies and bottle flies are other types of flies that sneak indoors. They are about the same size as house flies but have a metallic green, blue, or bronze sheen to their plump bodies. They breed in animal waste and carcasses. If you’re seeing these flies in large numbers indoors, you may have a dead animal, such as a bird or squirrel, in places such as the attic or chimney, says Gray.

Little filth flies such as drain flies breed in sludge and decaying matter that can build up in drain pipes, says Oi. They resemble tiny moths and are about 1/16-inch long with yellow to brown-black hairy bodies and wings they hold over their bodies when resting. You’ll see them in the kitchen near drains and garbage disposals.

Fruit flies come in from outside, attracted to ripening produce on your kitchen counter, or they may be brought in on infested fruit. They’re about 1/8-inch long and have red eyes. They lay eggs on the surface of fermenting produce or in trash cans, drains, or recycling bins.

How To Keep Flies Away

Depending on what type you’re dealing with, your approach to controlling flies may differ. But these tips will help overall:

· Make sure window screens are in good repair. “These are your first defense against flies,” says Gray.

· Take out indoor trash bags at least once a week, says Oi.

· Tie bags up and seal tightly inside the garbage can to retain odors, and keep the can far away from entrances to your house, says Gray.

· Keep recycling bins away from the house, and clean regularly. Flies are attracted to fermentation, such as in alcoholic beverage cans, so rinse cans and food containers before tossing into the bin, says Oi.

· Place compost bins as far away from the house as possible, says Oi.

· Clean up pet waste every day, says Gray.

· If you’re not sure if you have drain flies, take a clear container, smear some petroleum jelly on it, and turn it upside down over the drain overnight. Drain flies will attempt to fly out and get stuck, says Oi. If you have drain flies, use a stiff drain brush and a drain cleaner to clear out sludge.

· Cover picnic foods with fine mesh food covers, says Gray. Flies carry pathogens on their bodies, but they also defecate and regurgitate while walking around on food!

· Discard rotting produce, and don’t leave food waste like banana peels on your counter, says Oi.

· Run a box fan if you’re sitting or dining outdoors. Flies don’t like fast-moving air. “Enough air movement to be considered a ‘bad hair day’ keeps them away,” says Oi.

· Hang sticky traps in the garage near entrances to your home. They’re not pleasant to look at but may help reduce the numbers that try to head inside when you open interior doors, says Gray.

Do Repellants Keep Flies Away?

Despite what you’ve heard, DIY “repellants” don’t keep flies away. That goes for bars of pungent soap, essential oils, sonic repellant devices, and hanging up pennies in bags of water, a favorite Internet myth.  “None of these theories are supported by science,” says Gray.

In addition, spraying insecticides to kill flies isn’t a good option. “Flies are resistant to most of the pesticides registered for their management,” says Oi. “And pesticides aren’t permanent. If you have a major infestation, you must find the source. They’re breeding somewhere.” You’ll need to contact a professional pest control company for assistance.

As for how to kill flies that make it indoors? Both Oi and Gray say the use of good, old-fashioned fly swatters is best. “It’s an effective, pesticide-free way to kill them,” says Gray.

Oi also suggests keeping sanitizing wipes handy to wipe down the swatter and the surface where the fly was smashed.