How Do You Get Rid of Gnats Inside the House?

Medically Reviewed on 5/12/2022

What does a gnat look like?

Gnats are tiny (about 1/8 inch long), dark, mosquito-like flies with antennae and long legs. One of the most effective ways of getting rid of gnats inside your house is to handle the breeding ground.
Gnats are tiny (about 1/8 inch long), dark, mosquito-like flies with antennae and long legs. One of the most effective ways of getting rid of gnats inside your house is to handle the breeding ground.

Gnats are small flies you may see in your sink or around your lit computer screen during the evenings. Despite their small size, they are full-grown adults. Only adult gnats grow wings and fly. Seeing them around is a sign that they are successfully breeding in your house.

Gnats are tiny (about 1/8 inch long), dark, mosquito-like flies with antennae and long legs. Their wings form a Y-shaped pattern. Their larvae are translucent worms with a black head capsule. While gnats are not considered dangerous, their presence can be a nuisance in the household. Most won’t bite.

Are these gnats?

Gnats is also a name used broadly to refer to different types of small flies including, fruit flies, fungus gnats, and drain flies.

Fruit flies are brown bugs mostly found around rotting or overripe fruits and vegetables. You will most probably find them flying around your fruit bowl, the trash bin, and open alcohol bottles. They thrive in the summer, but sometimes, you may also see them during the cold months in your house.

Fungus gnats mostly thrive in moist environments in the household. They are common in households with houseplants, and they lay eggs in wet soil. Their presence in plant nurseries means that you can bring them into your house with a plant without realizing it. You may find them in your houseplants' soil, or on the rim of the pot. A little disturbance of the plant might cause the fungus gnats to start flying around.

Drain flies are a type of fly typically found in places with stagnant water like drains, sewers, and septic tanks. This is because they lay their eggs in water. They stand out from fruit flies and fungus gnats due to their larger wings and furry body, which resembles a moth’s body.

What causes gnats inside your house?

Certain factors may cause gnats to thrive inside your house. Gnats like living in moist, food-rich areas. Common breeding spots include: 

  • Food spills in the house
  • Puddles
  • Under sinks
  • The garbage can
  • Overwatered houseplants
  • Moist houseplant soil
  • Leaking pipes in the kitchen
  • Moisture forming on the vents and windows 

A moist environment is an ideal place for female gnats to lay their eggs. After the eggs hatch into larvae, they feed, become pupae, then grow into full-grown adults. You may only notice their presence when they start flying around. The adults grow wings after going through the pupal stage.

In their larval stage, they mostly eat fungi and organic matter found in soil. This is why potted house plants are one of the gnat’s favorite places to breed. Unfortunately, their larvae sometimes eat the roots of the plant. This may damage your houseplant, and when they emerge as adults, they will become even more of a nuisance.

Gnats also breed outdoors in soil, but seeing adult gnats in your house during the winter can be a sign that they are breeding indoors.

How to get rid of gnats

One of the most effective ways of getting rid of gnats is to handle the breeding ground. Since they thrive in moist areas, find these places and get rid of the moisture. 

Consider doing the following:

  1. When you are watering your plants, drain excess water and take the plant outside to let the soil dry. Only do this if the weather is conducive, though. Also, take care not to leave your plant to wilt. When the soil is dry, take it back into the house and skip a day or two of watering.
  2. Fix leaks in water pipes around the house and get rid of moisture that might have collected in your kitchen, utility room, bathrooms, and crawl spaces.
  3. Pinpoint the areas that adult gnats like hanging out (most often near sources of light), and spray them with insecticides that contain pyrethrins. Make sure the label indicates the insecticide is meant for gnats. Also, read and follow instructions on how to use the pesticide.
  4. There are also insecticide products for potting soil. These can be helpful in managing indoor and outdoor breeding grounds. It's a less hazardous way of getting rid of gnats.
  5. Another way to get rid of outdoor sources of gnats is the use of helpful nematodes. These are worms that will eliminate gnat larvae in the soil.
  6. Traps. Trapping gnats using sticky traps for adult gnats and raw potatoes for larvae are effective ways to get rid of gnats. You can get sticky traps from a nursery retailer or a garden center. Try placing a yellow sticky trap in your houseplant’s pot or any other place they like flying around. This will help trap flying adult gnats. To deal with larvae, place a raw potato in the potting soil. Gnat larvae love raw potatoes so much that they will leave your plant’s roots to feed on the potato. After some days, dispose of the infested potato and replace it with a fresh one.

More tips to get rid of gnats at home

There are a few other simple tips you can use to control gnats in your home. One of them involves mixing sugar, water, dish soap, and apple cider vinegar in a bowl to attract and kill the flies. Gnats can’t resist landing into this mixture. 

You can also use red wine in place of water, sugar, and vinegar. A simple mixture of red wine and dish soap will also do the trick.

If you notice that gnats are hanging around your sink, drain, or plumbing fixtures, pour some diluted bleach into them. This will get rid of the gnats, their eggs, and larvae.

Will gnats go away?

Gnats are seasonal pests that thrive during the spring. With proper methods of control, they may eventually go away as the year progresses. Gnats have a short life cycle and will often disappear when the cold months start.

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Medically Reviewed on 5/12/2022
References
SOURCES:

Colorado State University: "Fungus Gnats as Houseplant and Indoor Pests."

Iowa State University of Science and Technology: "Watch for Fungus Gnats in the House and Take Action if Found."

MVOrganizing: "How do you get rid of gnats inside the house?"

NC State University: "Fungus Gnats Indoors."

Texas A&M University: "Drain Flies," "How to get rid of fruit flies in your house."

University of California Agriculture & Natural Resources: "Fungus Gnats."