How to Get Rid of Fruit Flies and Gnats

Know your gnats: there's a difference between gnats, fruit flies, and drain flies.
Traps made from vinegar, wine, or overripe fruit can help trap gnats and fruit flies.
Avoid overwatering your plants to keep fungus gnats away.
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Gnats are pesky little insects, whether they're invading your home or exterior area. The key to getting rid of them is understanding the different types of small flying insects, so you'll know whether you have gnats, fruit flies, or drain flies. Then, it's important to understand what's attracting them to your home so you can take the appropriate steps to get rid of them.

"There are several species of gnats and they all like saturated soil and organic matter from leaf piles, dead plants, compost, manure, and mulch piles," says David Price, associate certified entomologist and technical director for Mosquito Joe. In your home, gnats are drawn to overly-ripe fruit and even food stuck in your garbage disposal.

"They end up in your yard or around your house from a couple of different sources," he says. "For example, they can be brought in from a plant that has eggs in the soil, mulch that may have eggs or larvae, or from a neighboring property, woods, farm, or nearby wetlands."

While some gnats can contaminate your food by transferring bacteria from a dirty surface, Price says that in most cases, gnats are just a nuisance. And there are plenty of solutions that require little more than what you've already got lying around. But first, you should know what type of gnat you're dealing with.

Gnats vs. fruit flies vs. drain flies

"Gnat" is often used to refer to these common insects.

It's quite common to think that "gnats," "fruit flies" and "drain flies" are synonyms for the same small flying insects. But they are three distinct species:

Fungus gnats look like small mosquitoes (but they don't bite). They are usually dark gray or black in color. They're tiny, and they have long legs. "Fungus gnats can be found in or outdoors and the larvae will drain the nutrients of a plant," Price explains.

Fruit flies look like tiny house flies, and they have large, red eyes. They may be light brown or dark in color. "They are typically brought indoors from any fruit or potato that you buy at a store, and they will quickly move to the drains where organic material is building up. That's why a garbage disposal is a common location," Price says.

Drain flies are light in appearance, usually a beige/tan or light gray color. Their appearance is unique because they look quite hairy. "Drain flies are an indicator that water has been standing for a week or more. They often show up in a bathroom that hasn't been used for a while or if there is slime buildup in plumbing pipes," says Price.

How to get rid of gnats

A mixture of dish soap and vinegar will lure the gnats.

Fortunately, there are ways to rid your home and plants of gnats, fruit flies, and drain flies. Solutions below include both traps that will attract any type of gnat and specific solutions for clearing your plants of fungus gnats and your drains of drain flies.

Keep in mind that these are all short-term solutions, and the concoctions will need to be replaced/refreshed every week or two.

Method 1: Vinegar trap

Price recommends placing a few tablespoons of apple cider vinegar, a few drops of dish soap, and a tablespoon of sugar in a bowl and then stirring the contents. "Set your bowl in an area where gnats are prevalent, like your kitchen or bathroom," he says. The gnats will be attracted to the sugar and vinegar, but the dish soap will coat their wings making them unable to fly away.

Method 2: Wine trap

If you have some stale wine, Price suggests pouring it in a small vessel and then adding two drops of dish soap. "Place the mixture in gnat-filled areas of your home and wait for the bugs to drop in," he says.

Method 3: Fruit trap

If you choose this method, Price advises covering a jar of rotting fruit with plastic wrap and then punching holes in the wrap. "The gnats will enter the jar and get stuck in it," Price says.

Method 4: Fan

Vera Peterson, president of Molly Maid, recommends using a small household fan to get rid of gnats. "Turn your fan on a low setting — this moving air will make it tough for gnats to fly, creating a miserable environment for them," she explains.

Method 5: Salt, baking soda, and vinegar

If the gnats are congregating around your drain, Peterson recommends another concoction: Pour 1 cup of vinegar and a half cup of salt and baking soda down the drain. Let it sit for at least two hours and then pour boiling water down the drain.

Method 6: Boiling water

In addition to using one of the methods above, Peterson recommends pouring a small pot of boiling water down your drain on a weekly basis to prevent it from developing into an environment gnats are attracted to.

How to get rid of drain flies

To get rid of drain flies, Price has one primary recommendation:

"Combine 1/2 cup salt with 1/2 cup baking soda and 1 cup of vinegar and pour down the drain." Leave it overnight, and in the morning, pour boiling water down the drain. "This is a natural remedy that will clean the plumbing pipes and remove the breeding grounds for these flies," he explains. "Additionally, any product that will break down the slime or organic matter that is building up in the pipes will assist in the long term."

Keeping gnats at bay

An ounce of prevention is worth a pound of cure. Peterson recommends keeping your home – and especially your kitchen sink drains and toilets clean and clear. Dispose of any fruit or other produce past its prime, and do the same with any cut flowers.

Regarding houseplants, Pangborn says gnats are looking for consistently moist environments where they can lay eggs — and that's why potted plants are so attractive to them. "The trouble comes when the top layer of potting mix doesn't dry out between waterings, since the top layer is where the gnats settle," she says. Gnat infestations typically occur with plants that need a lot of water or plants that are overwatered.

"One of the best ways to deter fungus gnats is to ensure the top layer of soil is not kept constantly wet." Instead of overhead watering (with a faucet or water can), Pangborn recommends putting your potted plant — be sure it has a drainage hole — in either a tray or sink that's full of a few inches of water.

"Allow it to sit in the water for anywhere from 30 minutes to an hour; during this time, the water will soak into the bottom of the soil through the drainage hole, and slowly saturate the root ball from the bottom," she says. After you remove the pot, let the excess water drain before putting it back in its saucer or cachepot. "This technique of bottom-watering ensures your plants get the water they need while avoiding the environment that gnats love."

And she has one last piece of advice. "Since the top layer of soil is where gnats like to be, another trick to keep them away is to replace the top 1 to 2 inches of potting soil with something that doesn't hold water, like perlite."

Insider's takeaway

Whether they're in your home or outside, gnats are problematic. You probably have most of the ingredients that can be used to bait and trap them, such as vinegar, wine, and rotting fruit. However, since rotting fruit can also attract gnats, ensure that you're thoroughly cleaning your kitchen and garbage disposal.

Regarding plants, overwatering them is likely leading to your gnat problem. Consider watering plants over a sink or drain and then letting the water drain out.

When she's not writing about business trends for The Economist, or legal trends for the American Bar Association Journal, Terri spends her time covering trends in buying and selling homes, mortgages, home improvement, and home products. She has bylines at Realtor.com, Bob Vila, Apartment Therapy, The Spruce, Real Simple, Real Homes, Yahoo, The Daily Beast, Investopedia — and several other companies that you've probably heard of.

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