Q&A for How to Get Rid of Drain Flies

Most drain fly cases can be solved using DIY remedies. If the infestation is severe or you cannot fully get rid of them after several attempts, then a professional plumber or exterminator would be a good idea.

Yes, stagnant rainwater can be a breeding ground for drain flies. Puddles, outdoor buckets, or even potted plants can collect water and attract drain flies. It's possible they are migrating indoors from a source like this.

Drain flies often appear in drains that are rarely used or maintained. If the drain had any water, hair, or other residue inside from the last time it was used, it makes a prime breeding ground for drain flies.

Nope! Drain flies are annoying, but harmless. You have nothing to worry about (unless what you're seeing are not drain flies).

It depends. If there is a window near your sink, then close the window. If that doesn't work, take a piece of clear tape and tape it over the drain, sticky side down. In the morning, check the tape. If there are flies on the tape, that is your culprit.

The larvae can, but not adults. If you have them, the larvae came up the pipes.

No, drain flies do not bite people.

I poured a few cups of bleach in the toilet tank while it was filling up, left it for a few minutes, then flushed it a few times. It worked for me, but I've heard it damages the wax seal. So far it's been okay.

These are drain flies; they don't compete with houseflies. You just don't have houseflies.

A sump doesn't supply food for the flies. Drain flies would be coming from drains connected to sewers, such as sinks and floor drains. It is highly unlikely that you do not have a floor drain if you have a sump pump.

Purchase some diazinon and treat the area surrounding the kennel. You can use the liquid or granules. If there is a concern about the dog getting to it, you can try sweet lime (powdered dolomite limestone) instead; however, this is only a blocking aid as opposed to something that is tracked to the nest and kills them.

Not that I know of, drain flies usually stay close to their nest and usually the nests are in drains and gutters, hence the name. I've never seen them around my plants.

Use clear silicone caulking to seal all gaps and joints around the pit and piping. The flies will find any space they can to get out of your sewage pump and piping. This will also help with odor. Make sure it is silicone, though, as silicone will not crack.

The larvae can spread through the pipes. If your drains have a sludge build up, as most do, then the larvae could hatch and then reproduce in your drains. However, if you keep your drains clean, the larvae and adults will not have a breeding ground to reproduce and inhabit your apartment. I suggest cleaning drains once a month. All drains should have water run through them at least once a week so the p-trap does not dry out.

Terro. Buy it at Home Depot. Bait where you are seeing active ants. Let them eat it and take it back to the colony to feed them. Do not wipe anything down or kill the ants. Let biology take its course. Clean after they are gone.

I recommend getting a second opinion, because what you described is a springtail.

Drain flies breed in the biological scum on the walls of your exposed drain pipes inside your home. The scum is mostly above the U-shaped trap under each sink or drain pipe. Toilets have a U trap that has minimal scum adhesion, but drain flies can still breed under the rim of a toilet where scum has built up. If flies are entering your home from the sewer-side of your plumbing, then it is likely that your sewer pipe is venting into your home. Consider periodically adding water to infrequently used drains (including toilets) in order to prevent sewer gases (and drain flies) from making their way inside, and consider capping any unused drains.

Consider contacting a pest-control expert, who will assess your drainage system and provide the best solution.

Once you identified the source of the drain flies (e.g., drain hole), you can slowly pour the gel directly into the drain hole, ensuring that the gel flow through the sides of the pipe.

Get basement waterproofing and that will fix the flooding issue. The flies will leave when the flooding stops.

These are fungus gnats. Get rid of them by not watering so much. Allow the plant soil to dry out well between watering and don’t use so much water when watering the plant.

They're probably drain flies or psychodidae, and they usually live in damp and dark places.