How to Get Rid Of Drain Flies Fast

Last Updated on: January 3rd, 2021 at 10:41 am

Drain Flies also known as moth or sink flies are a common nuisance in homes. These flies live and breed in the organic matter present inside moist drains and hence they are mostly found in kitchens and bathrooms.

Drain flies are not a harmful breed of flies and despite the fact that they come from drains, they do not transmit human diseases. And because of this, they have become an integral part of many water-dependent ecosystems.

Although they are harmless, however, their presence in your bathroom or kitchen can make you feel yucky. In this article, I am going to show you how you can get rid of these drain flies.

But before we move ahead, let’s make ourselves familiar with these pesky creatures.

How to get rid of drain flies

Signs of Drain Fly Infestation:

Before learning how to get rid of drain flies, it is important to find out the drain fly-infested areas. To find this we have two methods, you can use any of the two methods:

1. Spotting the Drain Flies: This is a very simple way to identify the drain fly-infested areas. Here, you have to find out the drain fly adults by the naked eye. The adults can be spotted resting on walls and ceilings of the infested areas. And as these flies are not good at flying so their source i.e. (breeding area) is very near to the infested area.

So, when you spot some adult drain flies, find a nearby pipe or a drain. The drain or the pipe will be acting as the breeding source for these flies. In case there are multiple pipes or drains near the infested area then you may need to use the second method to find the actual breeding source.

2. Drain Test: In this test, we are going to cover all the drains outlets and pipes with sticky tape, so that when drain flies try to come out of the source they get stuck to the tape, giving us infestation poofs.

Follow the below steps to do this:

1. First of all, clean and thoroughly dry the drain areas in your kitchen and bathroom.

2. After this, in the evening (this is important because drain flies are most active during the night), place a piece of clear tape over the drain outlets, pipes, etc. in your kitchen and bathroom, place the tape with the sticky side facing downwards. Do not completely cover the drain with tape, as this will prevent flies from coming out of the drain.

3. Leave the tape overnight or a weekend if possible. After that, check the tape, if you find any flies sticking to the tape, you have found the breeding source. If not, then repeat the test for 4 more nights to account for differences in the breeding cycle.

Now let’s see how to control the growth of drain flies.

Short Answer – How to Get Rid of Drain Flies:

Here are the ways to get rid of drain flies:

  • Clean the drains using Drain Cleaning Gel. Drain cleaning gel is specifically formulated to remove the organic matter from the pipes thereby cleaning the drain fly breeding source.
  • Use a Liquid Dish Soap Spray. Dish Soap contains borax, which has insecticidal properties. You could add 7 drops of dish soap with 2 cups of warm water and spray it directly over the drain flies to kill them instantly.
  • Set up a Sugar and White Vinegar Trap for Drain Flies. Take a cup and add ¼ cup white vinegar and ¼ cup sugar. Add 5 to 10 drops of dish soap. Leave the cup overnight, and the next morning you would see a lot of dead drain flies in the cup.
  • Occasionally spray drains with IGR (Insect Growth Regulator). IGR’s prevent the drain fly eggs from hatching and mutate the larvae so that they cannot pupate. Doing this reduces the chances of any future infestation.

Long Answer – How to Get Rid of Drain Flies:

getting rid of drain flies

For our convenience, we will divide the process of getting rid of drain flies into two parts. The first part will deal with the cleaning of drains to destroy the drain fly eggs and larvae, while the second part will deal with the killing of adult flies.

So, here we go:

Part 1: Destroying the breeding source:

Now once you have identified the breeding source, you can begin the process of eliminating the slime and dirt deposited in your drains where these flies breed.

1. First clean the drain, from outside. And then pour 2-4 liters of warm water to moisten the drain.

2. After this, use a metal pipe brush and push it through the pipe, move it in an up and down motion to clean the sides of the pipe. You could also use a plumbing snake to pull out the grime.

3. Next, pour a drain cleaner gel into the pipe trying to coat the sides of the pipe. Drain cleaner gel is specifically formulated to remove the organic matter from the pipes.

Many people say that instead of drain cleaning gel you could also use boiling water and bleach, but these methods are not effective against drain flies because drain fly larvae can survive under high temperatures.

4. After a few hours of application of the drain cleaner gel pour plenty of water. You could also use a plunger to flush any remaining organic matter trapped in the pipe.

Part 2: Killing the adult Drain Flies:

After removing the drain fly eggs and larvae by cleaning the drain, you are only left with the adult flies. Since they now have no place to lay eggs, your drain fly problem will disappear when these adults die. To kill these adult drain flies you could use sprays or swatters. Below is a list of some methods that you can use to kill the adult drain flies:

1. Using Chemical Sprays: You could use chemical sprays to kill the mature drain flies. But the problem with chemical sprays is that they are toxic and hence cannot be used if the infested area is the kitchen.

2. Using Fly Swatters: As drain, flies are mostly seen resting on the walls so it is much easier to kill them using a mechanical fly swatter. But after killing them make sure to clean the bloody mess from the walls using a damp cloth.

3. Using Liquid Dish Soap Spray: Dish Soap contains borax, which has insecticidal properties. You can take an empty spray bottle, add 5-7 drops of dish soap, and then add 2 cups of warm water. Shake the mixture and spray on the drain flies to kill them.

4. Using a Trap for drain Flies: This method is good if the infested place is your kitchen. Take a bowl and fill it with an equal amount of sugar, water, and white vinegar. Add 5 -10 drops of dish soap. Leave the bowl overnight beside your kitchen sink. The fragrance of this liquid will attract the drain flies and as soon as they land on it they will be immediately drowned and dead.

What are Drain Flies?

Physical Appearance:

Drain flies are very small (typically 2 to 5 mm in length), light grey or tan colored flies with a short body and leaf-shaped wings. The body and wings are covered with small hair which gives it a fuzzy appearance. Wings are too large when compared to the body, drain flies fold their wings in a characteristic roof like pattern.

Behavior & Habitat:

Drain Flies are typically nocturnal insects and are associated with damp habitats. They are not very good at flying, they fly in a jerky, irregular pattern. Adults can be spotted resting on walls and ceilings of the infested areas. Another important thing about them is that they do not bite.

Feeding Habits:

Drain flies feed on damp, organic resources that are easily available near the infested areas, such as decaying vegetation, and other microscopic plants and animals.

Life Cycle:

Drain flies lay eggs mostly in decomposing organic matter found in drains and pipes. The eggs are brown or cream in color and hatch in 32 to 48 hours. The larvae feed on the gelatinous drain matter and reach the maturity age in 9 to 14 days. Drain fly larvae are known to survive in high temperatures and low oxygen conditions. Drain Flies have a life cycle of 1 to 3 weeks.

In a small number, these flies can also be considered beneficial as their larvae can break down the materials that clog drains.


  • Drain flies can grow quickly and hence they can multiply in a few days creating a nuisance for you.
  • Though drain flies are not reported to transmit any diseases to humans, they are capable of doing mechanical contamination of foodstuff as they originate from a filthy source.
  • They can intensify bronchial asthma in some people.

Now let’s see how to find the infested areas and breeding sources of these drain flies.

How to Keep Drain Fly from Returning:

To ensure that drain flies do not return to you home again, follow the below tips:

1. Keep the drains clean and clog-free.

2. Make sure that there is no stagnant water in your bathroom or kitchen.

3. Occasionally spray IGR (Insect Growth Regulator) in your drains. IGR spray prevents the drain fly eggs from breaking out of the larvae stage and hence can greatly reduce the chances of any future infestation.

So, this was it. Hope you will find these methods useful and remember if the problem is severe then you may need to seek some professional help.


Recommended Reading: How to Eliminate House Flies

About Ankit Zadi

My name is Ankit Zadi, and I can call myself a 'Fly Expert'. My adventures with flies began when we shifted to our new house seven years back. My goal on this website is to share everything that I know about flies. Check out my full story here.


  1. Marty Howell says

    Will drano work for drain flies? If not what chemical can I use? Thanks

  2. Does gasoline odor kill the larvae and remove the breading site ?

  3. Regina Benson says

    We got rid of them by cleaning out the P traps manually. Does this ensure reinfestation?

  4. Michelle D says

    Thanks for the information! I am going to try the tape tonight to make sure where they are coming from. And hopefully use the drain cleaner tomorrow to kid rid of them!

    • I don’t know where you live but once our temps. got into the 90’s-100’s my drain flies completely disappeared.

  5. Drain flies became a problem for us after we had our septic cleaned out. Has anyone else had this problem?

  6. They hate meadow fresh Lysol spray. It makes them shrivel up and DIE.

  7. We’ve had a huge problem with drain flies for a while now. After manually cleaning the basement drain we are pretty sure they are coming from, using enzyme drain cleaner in every single drain in the house, and having Terminix spray for them, it’s gotten better. We are seeing very few live bugs compared to what we saw before.

  8. Since the adult flies die, we didn’t bother using toxic sprays – just vacuumed up the little bodies, whenever we saw them – alive or dead.

  9. We usually pick up a product at the hardware store called Vapona I believe its called. It does the job well for the adults. But it costs around 12 bucks. Tonight I will try this recipe in the bowl. Since we have some borax somewhere here.

  10. I’ve found that treating the bath drain to a drain cleaner gel treatment (followed by hot water) every 6 months or so keeps them away.

  11. I have had this strong hatred for these drain flies and i think i have killed thousands on sight with a rag. Now, trust me, i will be killing more and more with the borax and HOT water infact!

  12. Every year we get a nasty infestation of these drain flies at work. What I found to work the best is to pour baking soda down the drain and then pour vinegar. Did this on a Friday and came back to work on Monday and all of them were gone.

  13. I use a small dish with a tablespoon of dish soap and add maybe a third to one half cup of apple cider vinegar. Put it out and leave it. In the morning you will be surprised. This works for fruit flies as well.

  14. I had a persistent problem with these drain flies for five years. I even paid a company $125 to find where they were coming from, but they were unsuccessful. I constantly cleaned all the drains. Then, accidentally the problem was solved by the use of PLINK in the garbage disposal. By plinking once a week, I no longer have the problem!!