How To Get Rid of Sewer Flies In A House

These little flies are the worst. Most people associate them with dirty and unhygienic houses.

In case you didn’t know, sewer flies are also known as “Drain flies.”

Just as their name suggests, they’re commonly found around drains in your home. These include all the water points like your kitchen sinks, toilets, and bathrooms.

Sewer fly biology

The intel you’re about to receive is crucial in your mission to rid your house of sewer flies.

After all, aren’t you supposed to know more about your enemy before you head to the battlefield?

Sewer flies undergo complete metamorphosis like most of their fly relatives. The cycle can take anywhere from 8 to 24 days.

Unfortunately, sewer flies are known for their habit of mass egg production. We’re talking an average of 30 to 100 eggs. These pesky insects can hatch eggs every 24 to 48 hours.

Also, where they choose to lay their eggs is random. It might be in the garbage bins, sink water traps, or some damp open area. They can be anywhere as long as organic waste materials are laying around. 

The eggs hatch to larvae that feed on decaying organic materials. This stage lasts anywhere from 9 to 15 days before the pupa stage.

The pupa stage only lasts 20 to 40 hours before a new adult sewer fly is introduced into your happy home.

Fortunately, sewer flies don’t fly as much as other flies. You’ll mostly see them taking small flights and resting in shaded areas during the afternoons.

Their best hangout? On and around your kitchen sinks and toilets.

Sewer back-ups create the perfect breeding spots for sewer flies. You’ll now have two problems to deal with: A smelly house and a possible sewer fly infestation.

Why not take the initiative and check this Surex article on the sewer backup coverage options?

Are sewer flies harmful? Do they bite?

I know this one thing you’re eager to know. 

No, sewer flies don’t bite. In fact, they are “harmless” flies. You don’t have to worry about itchy bites or possible infections.

This might shock you, but sewer flies can be considered “useful” in the biological circle of life. They’re among the organisms responsible for breaking down organic waste in wet drainage systems. It’s sad to say, they also have a use.

But does this mean they’re welcome into our homes?


Sure, they might be harmless, but they’re an uncomfortable sight to behold. There is nothing cute or pretty about sewer flies.

Plus, who wants to host a group of fast-breeding guests who will probably take over their kitchen or toilets?

How to check for sewer flies in a house

With years of experience in pest extermination, Permakill Exterminating provides excellent services when it comes to the inspection and removal of sewer flies and all other pests. Continue reading as we get into the little details provide by these pest extermination experts on how to get rid of sewer flies in your house.

Inspect the drains

The first biggest clue is in their nickname, “Drain flies.”

What should you be looking for?

Sewer fly larvae.

Take a knife and scrape on the kitchen drain sides. Any sign of slime? Yes? Then it’s likely that you’re dealing with a possible sewer fly infestation.

The duct tape trap

You can outsmart these sewer flies using duct tape.

All you have to do is get some duct tape and cover all your drains.

After taping, take a sharp knife and make some airflow holes on the duct tape.

Let it stay there for a while.

After a few hours, remove the duct tape and check to see if there are any sewer flies caught by the trap. The more the flies, the more serious the infestation.

Check the floor slabs

The second most favorite place for sewer flies is under the floor slabs.


Because in most houses, the plumbing pipes are installed under the floor slabs.

A small leak or crack is more than enough to create a favorable moist breeding ground for sewer flies.

You can use “the duct tape method” to check and remove some sewer flies from under your floor slabs.

How do you fix this?

First, remove the slab, destroy the sewer fly breeding spot, then repair the broken pipe. However, sometimes the process might not be as straightforward as it sounds.

The leaking pipe might be several inches into the ground, thus not easy to spot.

In such a case, you might want to call in a plumbing professional.

Inspect the pump pits and sewers

In most buildings, these spots are in the basement. These places can be a bit tricky since they can be breeding sites without necessarily hosting adult sewer flies.

You don’t have to spot adult flies.

Is there stagnant water or moisture on and around the place of suspicion? Then you have to inspect the area.

The shower area

Is there space behind your shower wall, or have you seen sewer flies hovering around your shower area?

You might want to drill a hole into the shower pan or the wall behind the shower.

Sewer flies are suckers for light and are likely to start jetting out of the drilled hole. That is when you’ll you had a sewer fly infestation happening from right under your nose.

Ward off all unwanted guests

Although drain flies don’t pose a health hazard as such, exposed sewers and leaking water can be a source for several other flies and insects as well. 

These areas can be attractive to stinging bugs like wasps and other bees that dwell well on them. However, a wasp infestation can go undetected and be dangerous to live near. A wasp removal process is highly advised with sewer flies; in case of a wasp or bee infestation chances to keep yourself out of danger

How to get rid of sewer flies naturally

Natural solutions are a good idea since most of these places are near food preparation spots.

Hot boiling water

We advise you to heat and pour hot boiling water into the drain at least twice a week.

The hot water will destroy the eggs, kill the larvae, and break down some organic waste that would have provided food for the sewer flies.

A mixture of baking powder, salt, and vinegar

I’m sure you are familiar with some of the ingredients listed above, like vinegar and salt. Both of those are great cleaning agents.

Baking powder is more a facilitator. It reacts with water and expands, thus pushing the formula through the cracks and crevices.

A mixture of soap, water, sugar, and vinegar

All you have to do is prepare the mixture in bowls, then leave them near the suspected breeding grounds. The thick sugar solution will attract and trap those pesky sewer flies.

Apple cider vinegar and plastic wrap

Fill a jar with a layer-inch of apple cider vinegar then cover the top opening with plastic wrap.

Also, make sure you punch some holes into the plastic wrap. The vinegar will attract the flies into the jar then the plastic wrap will stop them from leaving.

Kevin Darabont
I am a freelance writer who loves to craft, home decor improvement, and active DIYers. I am happy to share my knowledge and experience to the world and learn new things everyday.