How to Get Rid of Drain Flies: Simple, Yet Effective Methods

Learn how to get rid of drain flies naturally, as well as using chemicals, and how to prevent the infestation from happening again
Phyllis McMahon
Phyllis McMahon
Research Writer
Phyllis teaches English Literature at a local college and loves writing in her free time. She’s also a great cook – her British beef Wellington is something the best res read more
Reviewed By
Chas Kempf
Chas Kempf
Expert Consultant
Chas works in a professional pest control company and knows all the nuances of this job. Also, he’s a fantastic tennis player and loves to organize BBQ parties for his fam read more
Last updated: August 12, 2023
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Sometimes, it feels as if there’s a fly for everything. You’re not alone if that’s what you think about drain flies. These gnat-sized, moth-looking tiny flies are usually found in drains with stagnant water. And if that sounds like a problem you have, then it’s time for you to learn how to get rid of drain flies.

Believe it or not, drain flies don’t harm anything; they’re more of an annoyance. However, they also indicate a more significant problem you may not know yet. If you’re starting to see drain flies around, take note because you now have two issues to tackle: the flies themselves and the underlying cause. Read more to find out how to get rid of drain flies forever.

How to Identify a Drain Fly?

Before you start dealing with them, you need to know how to identify drain flies first. The biggest giveaway is if they’re hovering around the sink or drain. They’re about the size of a gnat – about an eighth of an inch. They also look quite fuzzy since they’re covered in scales that become dust when they get hit.

Because drain flies only eat algae and similar organic matter from sludge, they shouldn’t be flying near solid food sources such as fruits or vegetables. They also shouldn’t be biting you. If any of those apply, you have something other than a drain fly.

Drain Flies vs. Fruit Flies

How to Get Rid of Drain Flies: Simple, Yet Effective Methods

Learning how to get rid of drain flies in your house should involve knowing the difference between drain and fruit flies. That’s because they’re both symptoms of two different but related problems. Drain flies feed on sludge and live on stagnant water caused by improperly drained food scraps; fruit flies feast on overripe or rotten fruits and vegetables.

The first main difference between the two is their appearance. Even though both are about the same size, fruit flies have bright red eyes. They also lack the signature fuzzy, moth-like look that drain flies have. And most importantly, fruit flies are always flying around, while drain flies typically stay where they are. That’s why insect killers like electric fly swatters won’t work well against drain flies; there’s nothing to swat if they don’t fly.

What Causes Drain Flies?

Drain flies love stagnant water that has anything decaying on them. These don’t necessarily mean your drain, but a sink or shower drain is the most common place to have standing water with organic material. Once they catch the scent of whatever is in your drain, they’ll try to make their way inside your house so they can feast on the sludge.

What Harm Can Drain Flies Do?

You’re probably trying to find out how to get rid of drain flies naturally because you’re worried about the potential damages a drain fly infestation might cause. The good news is these pests don’t cause any harm. They’re more of an annoyance, always hovering above sinks and drains, especially during the evening. They can’t bite you, so you don’t need to worry about any diseases from them.

However, they let you know that you have a standing water problem in your pipeline. The drain flies are there because your drain gives them a reason to be there. If you see them flying around, remember that getting rid of them means addressing a bigger problem with your home’s pipework.

How to Know If You Have Drain Flies

Are you starting to find small flying insects around your home but you’re not sure if the drain flies or not? To make sure you’re targeting the right pest, here are some steps you can take to determine whether you have drain flies or not.

Duct Tape Test

How to Get Rid of Drain Flies: Simple, Yet Effective Methods

This method also doubles as an inexpensive, homemade drain fly trap. All you need is a small strip of duct tape. Stick it on top of the drain, adhesive side down, and make sure it’s covered. Leave it overnight because drain flies are active at night; they’re more likely to get stuck on the adhesive as they try to move around.

If you’re not sure which drain they might be coming from, do this test on multiple drains at once. Once you check the duct tape the following morning, the one with the most drain flies is your problematic drain. And if you happen to have stray pieces of fruit down your drain or garbage disposal, the duct tape test can help determine how to get rid of fruit flies in the drain.

Check for Larvae

Checking for drain fly larvae yourself is another surefire way of checking whether you have a drain fly problem or not. If the sludge or clog is visible on your drain, see if you can pull it out using a drain pipe brush or similar. You can also scrape a sample from the drain. Check for long and thin tubes that may or may not have wings yet. If you find them there, drain flies reproduce in that drain.

However, if you don’t find any larvae, don’t assume that the drain is scot-free. They might be further down where you can’t easily reach. Perform this test alongside the duct tape method to confirm your suspicions. And if all else fails, you can always opt to clean the drain itself as a preventive measure.

How to Get Rid of Drain Flies Naturally

Did the tests indicate the presence of drain flies in your pipe? The good news is you can deal with them using natural products. Here’s how you can do that.

Boiling water

One of the easiest ways to get rid of drain flies is to pour boiling water down the drain. Do this about twice a day for a week, and you should start seeing some results. Not only does the boiling water kill the larvae, but it should also help loosen whatever is clogging your drain. Keep in mind, however, that this may not be an option if you have PVC pipes. The last thing you need is to damage your pipework.

Vinegar and baking soda

How to Get Rid of Drain Flies: Simple, Yet Effective Methods

These materials should be readily available from your cupboard. If you don’t already have them, make sure you buy them immediately, as they are great for cleaning and repelling other insects. You can technically get away with learning how to get rid of drain flies with vinegar, but the baking soda acts as a scrubbing agent.

Here’s how to get rid of drain flies with vinegar and baking soda:

  • Pour ½ cup of baking soda into your drain. You can also add the same amount of salt as a disinfectant.
  • After pouring the baking soda, pour a cup of white vinegar. The vinegar should cause the baking soda to fizz. Leave it for a few hours, or ideally, overnight.
  • Rinse the drain with either boiling water or hot water from your tap. Repeat this process in a few days if you still suspect drain flies.

You can also add a few drops of dish soap to attract and trap any drain flies attempting to escape. The soap is too thick and slippery for them to move. And if you want to double down on attracting the drain flies, you can sprinkle some sugar. The sweetness will attract the drain flies, but the soap will keep them in place.

Apple Cider Vinegar Trap

Here’s another way of how to get rid of drain flies with vinegar: by using an apple cider vinegar trap. The steps are simple:

  • Find a jar or container and pour some apple cider vinegar. Do not fill the jar.
  • Cover the jar with cling film, then poke small holes all over it. You want to make the holes large enough for the drain flies to enter.
  • If you want to make the trap even more effective, add a few drops of dish soap into the jar. The soap will make it harder for the drain flies to escape.

This method eliminates the adult flies first, preventing them from laying more eggs. Of course, you’ll have to wait for the larvae to mature before you’re completely rid of them, but you can expedite the process by using the boiling water or vinegar method. The best place to use this trap is near drains that are not in frequent use, so keep this method in mind when trying to plan how to get rid of drain flies in the basement.

How to Get Rid of Drain Flies Using Chemical Remedies

Just want to skip straight to commercially available remedies instead of relying on homemade ones? Or maybe you’re trying to plan how to get rid of drain flies in the bathroom, and you don’t want any lingering vinegar smell? Worry not because chemical remedies can also take care of your problem, regardless of whether you’re learning how to get rid of drain flies in the shower or anywhere else.

Commercial Drain Cleaner

If the boiling water or vinegar method didn’t clear your drain, you could always use commercially available drain cleaners. The repeated cleaning action and the chemical will eliminate any lingering drain flies and their larvae. Always make sure you use the product according to instructions and pay attention to its active ingredients. If you’re trying to learn how to get rid of drain flies with ammonia, you shouldn’t use a bleach-based drain cleaner.

Chemical Sprays

How to Get Rid of Drain Flies: Simple, Yet Effective Methods

Mosquito killer sprays can also work against drain flies, as these products are formulated to kill similarly-sized insects. To save you time, we have tested and reviewed some of the best mosquito killer sprays out there. Just be careful not to spray them around things you use daily, such as toothbrushes.

You can always use a drain fly kit if you’d rather focus on drain flies instead of multipurpose sprays. These kits are already put together for you, so you know each product will work together. All you need to do is use each product according to instructions and watch the drain flies disappear.

When Is It Time to Call a Professional?

If your efforts in learning how to get rid of drain flies in garbage disposal are proving fruitless, it might be time to call in a professional. Professional exterminators know exactly what to use against these annoying pests without compromising your pipework. They can also advise you on keeping the drain flies from returning.

Keep in mind that if your drain fly infestation is severe, it’s an indication that you have a serious standing water problem somewhere in your house. If there aren’t any obvious water sources around, you might have a blockage somewhere. You’ll need the help of a plumber to get that cleared. Plumbers are especially helpful if you’re trying to plan how to get rid of drain flies with a septic system.

How to Prevent Drain Flies

How to Get Rid of Drain Flies: Simple, Yet Effective Methods

Thankfully, preventing drain flies doesn’t require anything extra from you. Here are some steps you can take to avoid drain flies from bothering your life:

  • Regularly clean all of your drains. For high-traffic ones, make sure you use either a drain brush or a drain cleaner chemical to ensure there isn’t any gunk sticking to the side of the pipe.
  • Use filters to prevent any foreign material from falling into the drain. This is especially important for the kitchen sink, where bits of food regularly get left behind. If you have a garbage disposal installed, run it regularly.
  • Check inside and outside your house for potential spots with standing water. If it’s outside, clear it immediately. If it’s inside, look for the source. This may be a sign that there’s a pipe leaking.
  • If you live in an area where insects are active, consider installing light insect traps around your home. These traps work without input from you and can alert you of a possible infestation.


Do you have a few more questions about these harmless yet annoying insects? Here are the answers to some of them.

Do Drain Flies Bite?

Drain flies do not bite as they do not feed on blood; they feed on rotting organic matter. That’s why they love living on sewage treatment plants – they like to eat the algae and other rotten stuff on the sludge. If you have insects flying around in your home and you’ve been bitten by one, that’s not from a drain fly; that’s from something else.

How Do I Get Rid of Drain Flies Outside?

If you’re finding drain flies outside, you should immediately check for any puddles of water nearby. If you don’t find one, check for leaky pipes inside or outside your house immediately. Drain flies will be the least of your worries if you do have a pipe that needs repairing.

Final Thoughts

Even if you religiously clean your drains, there’s still a chance you’d have a drain fly visiting you. Don’t take that as a sign of lack of cleaning; instead, take it as a warning that there might be a leak somewhere.

And if there aren’t any leaks around your house, ensure you get rid of any standing water nearby. You wouldn’t want that anyway, as it could also become a breeding ground for mosquitoes. Regardless of what causes the drain fly to visit you, as long as you’re vigilant, you shouldn’t find yourself worrying about them too much.

We hope we’ve helped you understand how to get rid of drain flies. If you have any further questions, please don’t hesitate to contact a local exterminator. Remember, the best way to avoid problems is to practice good drain maintenance and keep your drains clean!

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