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Gnats fly in through open windows and doors or hitch rides on plants and produce you bring inside. Once they’re in, they breed in drains, potted plants, trash cans, and anywhere moisture collects. A few gnats turn into dozens fast because they lay eggs in all those damp spots you forgot existed.
The fix is mostly about eliminating their breeding grounds and blocking entry points. No traps needed (though they don’t hurt). Just make your house a terrible place for gnats to live.
1. Remove decaying organic matter
Start outside. Fallen leaves, rotting fruit, dead flowers, anything decomposing near your house is a gnat buffet and nursery combined. Clear it away from doorways and windows especially. Compost piles and garbage cans outside should have tight lids. If gnats can’t breed right outside your door, they won’t be hovering there waiting to slip inside.
2. Check for moist breeding areas
Gnats need moisture to lay eggs. Walk around your property and look for damp, dark spots. Under decks, around downspouts, anywhere water pools after rain. Fix drainage issues if you can. If not, at least know where the problem spots are so you’re not mystified about where they keep coming from.
3. Clean drains regularly
Gnats lay eggs in the slimy gunk that builds up inside drains. Pour half a cup of baking soda down the drain, follow with half a cup of white vinegar, and let it fizz for 15 minutes. The reaction breaks down organic buildup where larvae hide. Finish with boiling water to flush everything out. Do this weekly in kitchen and bathroom drains.
For stubborn buildup, use a long drain brush before the baking soda-vinegar treatment. You’re scrubbing away the film gnats need to lay eggs in. The brush reaches deeper than any liquid treatment, especially in those first few inches where most gnat larvae actually live. You can find drain brushes at hardware stores for a few dollars. Worth it if you’re dealing with persistent drain gnats.
4. Close windows and doors
Obvious, but people forget. Gnats are attracted to light, so they’ll fly toward lit windows at dusk. If you want windows open in the evening, make sure screens are intact with no tears. Check door sweeps too. A gap under a door is a gnat highway.
5. Remove exposed soil indoors
Houseplants with exposed soil are gnat magnets. Cover the soil surface with a half inch of sand or aquarium gravel. Gnats can’t get through it to lay eggs, but water still drains fine. You can also let the top two inches of soil dry out completely between waterings since gnat larvae die without constant moisture.
6. Get rid of standing water
Check plant saucers, pet bowls, anything that might have water sitting in it. Empty saucers after watering plants. Change pet water daily. Look for less obvious spots too like the drip tray under your fridge or condensation around AC vents.
7. Wipe up moisture
After cooking or washing dishes, wipe down counters and sinks completely. Don’t leave wet sponges sitting out. Gnats will find a damp sponge and treat it like a five-star hotel. Squeegee your shower walls after use if you’re dealing with a persistent problem.
8. Take out trash regularly
Don’t let kitchen trash sit for days. Gnats smell rotting food from across the room and will congregate around your trash can. Take it out every day or two, and rinse the can itself weekly with soapy water to get rid of any juice or residue at the bottom.
9. Use sticky traps
Yellow sticky traps work because gnats are attracted to bright colors and can’t resist landing on them. Place them near drains, on windowsills, next to houseplants, anywhere you’ve seen gnats hovering. They won’t solve a breeding problem but they’ll catch adults before they lay more eggs, which breaks the cycle faster.
Check traps every few days. If one’s completely covered in gnats within 24 hours, you’ve got a serious breeding site nearby. Use that information to figure out which drain or plant is the real problem. The traps are both solution and diagnostic tool.
11. Spray vinegar
Fill a spray bottle with equal parts white vinegar and water. Spray it around windowsills, doorframes, and anywhere you see gnats gathering. They hate the smell and will avoid it. Reapply every few days. Your kitchen will smell like a salad for a bit, but it fades.
12. Use basil leaves
Put a small bowl of fresh basil leaves on your kitchen counter or near problem areas. Gnats dislike the scent. You can also grow a basil plant on your windowsill for continuous coverage. Bonus: you have fresh basil for cooking.
13. Keep food packaging tightly closed
Gnats can smell fruit through a plastic bag. Use sealed containers for produce, especially bananas, tomatoes, and anything overripe. If you have a fruit bowl on the counter, check it daily and toss anything that’s starting to go soft.
14. Use insect repellent sprays
If natural methods aren’t cutting it, grab an indoor insect spray labeled for gnats. Spray around entry points and known breeding areas. Follow the label instructions. These work fast but you still need to fix the moisture and food source issues or they’ll just come back.