8 Natural Ways to Get Rid of Drain Flies Completely

Close-up of a drain gnat sucking blood on human’s skin.Sewer gnats, sink flies, drain flies – no matter what you call them, these pests are a royal pain. They may not do you any harm, but they sure love to buzz around your face just to drive you mad.

As you may have guessed, these flies feed on sewage and organic matter. Considering their hangouts and diet, it’s a surprise these pests don’t transmit human disease.

Even though these flies are harmless, females can lay between 30 and 100 eggs at once, and it takes just two days for eggs to hatch into drain worms. In just a few days, the population can start to get out of control.

How do you get rid of drain flies, and start enjoying your bathroom and kitchen again? The first step is to make sure you actually have sewer flies.

Read more about Drain Flies

What Do Drain Flies Look Like?

Drain flies are small – around 1.5 mm – 5mm in length. Their bodies are either gray or light brown in color, and their wings are light-colored.

Both their wings and bodies are covered in long hairs, which gives these flies a fuzzy appearance. Their fuzziness is what earned them the nickname “moth flies.”

Do Drain Flies Bite?

No. Drain flies do not bite (thankfully). They don’t sting either. They are nothing more than a nuisance.

Signs of an Infestation

Drain flies are attracted to moist areas rich in nutrient-rich organic material. Drains, sewers and septic tanks make the perfect habitats and breeding grounds for these flies.

The most common sign of an infestation is the presence of adult flies. They typically hang out near drains or breeding areas.

One surefire way to determine whether you have drain flies is to cover your drain with sticky tape. When the flies attempt to fly out the drain, they’ll stick to the tape. If you find any flies on the tape, you can be sure that you’re dealing with an infestation.

How to Get Rid of Drain Flies

A drain gnat on white background, with the words "How to Get rid of Sewer Flies" under the wing.
Source: http://www.iremovepest.com/

In some ways, drain fly larvae are beneficial because they consume the organic material that may be clogging your drain. Larvae have incredibly strong jaws and can cut through layers of thick, dense build-up.

But populations can quickly get out of control, which is why homeowners want to get rid of these pests as soon as possible.

We’re going to share the top methods for drain flies removal to help you get rid of these furry flying pests ASAP.

How to Get Rid of Drain Flies Naturally

The natural approach is usually the best first option. Most of the supplies needed for these methods are things you already have in your house.

1. Tackle the Root Source: Organic Material

Like it or not, you have moth flies because there’s a build-up of organic material in your pipes. It doesn’t sound pretty (and it isn’t), but it’s not uncommon to have this problem with older pipes.

If you get rid of the organic material, you take away the fly’s food source. Here’s how:

  • Push a metal pipe brush through the pipe. Brush back and forth as far as you can go to dislodge as much material as you can. We like the Houseables 9-piece brush set because it comes with a wide range of brush lengths and widths, which allow you to clean pipe walls with ease.
  • Pour a pot of boiling water to send the material down the pipes.

The pipe brush method is an effective way to get rid of these flies because it removes the root cause of the problem: their food source.

2. How to Get Rid of Drain Flies with VinegarA glass bottle of colorless vinegar with black tag on white backiground.

Vinegar has a million and one uses. Now, you can add drain fly killer to the list. Apple cider vinegar works best for this method, which will help you get rid of your fly problem without using harsh chemicals.

  • Pour apple cider vinegar into a glass. About ¼ a cup will do.
  • Cover the glass with plastic wrap.
  • Poke holes in the plastic wrap.
  • Set the trap near the drain.

The flies will be attracted to the vinegar. They’ll fly into the jar, dive down into the vinegar and drown.

3. Vinegar, Baking Soda and Boiling Water

The vinegar, baking soda and boiling water trick will do more than get rid of the flies – it will also leave you with squeaky clean drains.

Here’s what you’ll need:

  • 1/2-cup baking soda
  • 1 cup vinegar

Pour baking soda down the drain first, then add the vinegar slowly. The mixture should start bubbling and fizzing, and may come up out of the drain. Go slowly, so most of it remains in the drain.

Allow it to sit for an hour.

Next, pour a pot of boiling water down the drain to wash the solution away.

The vinegar reacts with the baking soda to create a bubbling and fizzing action. The mixture loosens build-up in the drain while also killing any flies, eggs or larvae that may be hiding inside. The boiling water is the icing on the cake, washing all the material down the drain.

4. The Bleach Method

If you don’t have vinegar on hand or prefer a stronger method, bleach is a great way to get rid of drain flies.

The bleach method is simple:

  • Pour a solution of 1 part bleach, 10 parts water down the drain.
  • Allow the mixture to sit for a few hours.
  • Flush the pipes with cold water.

The only drawback with the bleach method is that it will not scour the pipes like the baking soda/vinegar method will.

Not only can these natural methods get rid of the drain flies you already have, but using these methods on a regular basis can keep your pipes clean and prevent future infestations.

How to Get Rid of Sewer Flies – The Best Drain Gels and Traps

If you prefer taking the more efficient, conventional route, you have several methods available to you.

1. In the Shower

If you have drain gnats in the house, there’s a good chance your shower drain is the culprit. Hair, shampoo residue and skin can lead to build-up in the pipes, which attracts these fuzzy fliers.

How can you get rid of drain flies in the shower?

A bottle of Invade Bio Cleaner Drain Gel on the white.
Source: https://www.amazon.com

InVade Bio Drain Gel

Using natural probiotics, InVade’s Bio Drain gel is perfect for use in shower drains because it doesn’t contain any harsh chemicals or odors.

Other products that contain bleach and other harsh chemicals can turn toxic when your shower heats up.

Applied directly to drains, Bio Drain uses a formula of citrus oil and microbes to break down organic material build-up in your drains and kill drain flies.

Available in gallon size and affordably priced, this drain gel is a great choice if you have multiple shower drains that need treatment.

It works in kitchen and bathroom sinks, too.

Check pricing and availability.   

2. Kill Drain Flies In RVs

Treating RV drains can be a challenge in some ways, but easier in other ways. Homes have elaborate pipe systems, which can make it difficult to get to the root source. An RV has a less elaborate pipe system, but can be challenging to treat because you’re not connected to a permanent system.

To successfully treat your drain fly problem, you’ll need a product designed for RV use.


Safe for use in RVs, septic tanks, drain lines and even litter boxes, Bio-Clean contains natural bacteria enzymes that break down organic material in your pipes. By breaking down the material, you get rid of the fly’s main food source – the heart of the problem.

Enzymes feast on the waste material in your drains, and they move all along your pipe walls to keep your drains squeaky clean.

Regular use of Bio-Clean will keep your pipes clean and get rid of your drain fly problem.

And just a single two-pound container contains enough material for 100 treatments.

Check pricing and availability.

3. Get Rid of Drain Flies In a Restaurant

Commercial restaurants are a haven for sewer flies. With kitchen drains, bathroom drains, sinks and grease traps, restaurants are a drain fly’s paradise.

But in commercial settings, particularly those that serve food, it becomes even more important to keep drain flies under control.

They may not transmit disease, but they may contaminate food (they do eat waste material).

To tackle the problem, you need a commercial-strength product.

Shoo-Fly Professional Drain and Grease Trap

Shoo-Fly’s professional formula uses enzymes to keep drains and grease traps clean and free of drain flies.

This triple-action bacterial gel also removes grease from crevices, cracks and underneath heavy equipment.

The solution, which clings to pipe walls, contains a unique strain of the bacillus bacteria, which breaks down long-chain fatty acids. These fatty acids are what cause grease build-up.

Each gallon contains 600 billion cells, which multiply when poured into drains. These cells devour organic waste to tackle your drain fly problem at the source.

Biodegradable and non-toxic, this solution is ideal for use in commercial restaurants.

Check pricing and availability.

4. Eliminate Drain Flies In the Septic Tank

Septic tanks are the perfect breeding ground for drain flies, but keeping them free and clear of waste isn’t easy or practical. That’s the septic’s job after all.

To get rid of sewer flies, you need to use a product designed for use with septic systems.

FASTFLOW 3-in-1 Solution

FASTFLOW offers a 3-in-1 solution that acts as a microbial drain cleaner, drain fly killer and septic maintainer.

This one solution will keep your pipes clean and removes drain flies at their breeding sites. And the timed-release formula allows for continuous release of the bacteria over one month.

FASTFLOW’s formula contains surfactants and bacteria that break down grease and organic matter that clogs septic systems and invites drain flies.

Check pricing and availability.

These solutions will help you finally get rid of drain flies and prevent them from coming back in the future.

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