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How to Get Rid of Gnats In Drains


Insect infestations can spring up on you out of nowhere and when they do, you have got to be prepared. Creepy crawlies like gnats can be a homeowner’s worst nightmare. You can try to clean your house all you want, but until and unless you address the gnat problem individually, it is not going to subside anytime soon. They have been all around inside the drains and probably the sewer too. You don’t want to have them contaminate your house with the pollutants they have been carrying from under the drains, do you? There are plenty of ways you can overpower these tiny invaders and get rid of them for good. 

Why you shouldn’t delay a gnat problem in your drain

Gnats or drain flies are small flies having long and thin wings. They love places that are shaded, damp and containing decaying organic matter because fungal growth is encouraged in such conditions and their larvae can feed on this fungus. This makes drain pipes the ideal place for gnats. Outdoors, gnat larvae feeds on root hairs. Gnats are extremely prolific and if they find ideal conditions like warm temperatures that they can find inside greenhouses and homes, they will reproduce rapidly. The life cycle of gnats is usually four weeks. A female gnat can lay 100 – 300 eggs in decaying organic matter. If you don’t act soon, you will have a bigger problem on your hands than what you started out with. With each passing day, gnats will continue to multiple exponentially.

How to know if you have a gnat infestation

Usually, if you see adult gnats hovering around over the kitchen sink or the bathroom drain, you can be certain that there is a lot more where this one came from. However, as sneaky and tiny as they are, infestations are not always noticeable. Make sure that you inspect all the drains in your house to check for the presence of gnats. You can also stick transparent tape over each sink as a test to determine which one’s have a gnat problem. However, make sure you don’t cover the entire drain with the pipe because a drain that is 100% covered will not let have any gnats trying to fly through, so leave some drain holes open. Check up on the drains the next morning. If you have a gnat population inside of those drains, you’ll find them stuck on the tape.

Clean those drainpipes

Once you have identified the problem with the respective locations, it is time to take action. Moisten the drain with some running warm tap water, then grab a metal pipe brush and work it all the way inside the drain. Push it down as far as you can and pull it up in a repetitive motion. Twisting the pipe will also help remove the film of decaying filth on the sides of the pipe. After you are done scrubbing the pipe thoroughly, you are going to need a drain cleaner. Start applying around 125 ml of drain cleaner around the brim of the drain so that it drips down the pipe covering all sides. Although gel drain cleaners can effectively cut through organic matter, enzyme drain cleaners and bacterial drain cleaners do just as good a job as any other cleaner. Let the drain cleaner drip down and settle for 4 – 5 hours. Then, use warm water to drain the pipe and wash down the cleaner and dirt. To ensure there is no residual organic matter or pipe obstructions left inside, use a plunger over the drain.

Don’t leave out the individual adult gnats

Cleaning out the drainpipes will take care of the major gnat stronghold. However, you need to take care of the adult gnats flying around in your house as well. Electric fly exploders are great for this purpose. They attract gnats alongside other flies by emitting ultraviolet light and when the fly makes contact, they get trapped with the adherent surface of the trap and electrocuted. If you don’t want to buy an electric fly exploder, you can just go old school with a plain and simple fly swatter to kill the remaining individual gnats.

Trap and dispose

You can also make yourself a gnat trap. You can make it by filling an empty jar half way with apple cider vinegar. Gnats love this stuff. Poke holes with a nail through the lid and cover the jar with it. The scent of apple cider vinegar will attract gnats by the dozens. They can come inside the jar but won’t be able to leave. Place the jar in a place where you have previously sighted a gnat or two. Gnats tend to reside nearby where they are spotted and it is highly unlikely that a gnat infestation spreads from one area of the house to another.

How to make sure the gnats don’t come back

You’ve exterminated the lot of them but you also have to ensure they don’t come back. Remember, gnats prefer damp surfaces so always close the stopper in the sink before going to bed so no extra water seeps through. Don’t over water your plants either because stagnant water will attract gnats. If you have any leaks in your plumbing system, get them fixed right away. Also, keep your trash cans closed shut. If you leave your trash cans open, it’s just a matter of time before gnat feasting on the garbage come into the house. Finally, clean up your kitchen and dining area properly. Gnats live off your food scraps, so it’s imperative that you don’t leave any for them to feed on if you don’t want a gnat infestation on your hands once again.

Use Solutions Products to Eliminate Drain Gnats

Solutions Pest & Lawn has a number of great products which can effectively eliminate problematic gnats in drains. We recommend starting by clearing up the drain scum with a product called Forid Drain Gel Cleaner. Adding an insect growth regulator like Gentrol into the sink can help to prevent future reinfestations of drain gnats.

At this point, the drain gnats will begin flying out of your drain to escape. This is when you can hit them with spray products or trap them. We recommend an aerosol like Pyrid Aerosol to fog the area for a quick kill. If you'd rather not use chemicals, we suggest using Musca-Stik traps as an alternative.


We hope that with the help of our tips you could get rid of those scum eating gnats. For more helpful DIY tips or expert advice, be sure to send us an email with your questions at askapro@solutionsstores.com, give us a phone call at 800-479-6583 or live chat with us online!

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