Are drain flies a plumbing issue?

Author: Ephraim Padberg  |  Last update: Sunday, January 18, 2026

Drain flies are both a pest problem and plumbing problem because they infest your bathroom and/or plumbing fixtures. Even though flies can live pretty much anywhere, you can prevent them from living near you. We can help.

Do plumbers deal with drain flies?

Pest Control

The goal is to eliminate their breeding site. The most effective method for doing this is to call a plumber and have them mechanically clean the pipes of the slime and organic material that tends to collect in the pipes and drains.

Why do I suddenly have drain flies in my house?

What Causes Drain Flies? Drain flies thrive in stagnant and standing water. Common sources include slow or clogged drains, rarely used and unused toilets, refrigerator drain pans, and standing water created by leaking pipes. They typically enter buildings through basements, windows, and drains.

Do drain flies mean a broken pipe?

You have a broken pipe somewhere. They need organic content to breed. It is also possible that there was a broken pipe in the past, it was fixed, but the contaminate soil was not removed from the site and with ground water, the drain flies have a place to breed. They will come in the smallest cracks in a dwelling.

Are drain flies a health code violation?

The most glaring problem that drain flies may cause you is a health code violation. Drain flies are not known to cause diseases to humans, but they are known to trigger allergic and asthmatic reactions because of the dust and fragments from their bodies.

How To Deal With Fruit Flies And Drain Flies

How do I permanently get rid of drain flies?

Mix together 1/2 cup of salt, 1/2 cup baking soda and 1 cup of vinegar. Pour the mixture down the drain. Let sit overnight, then flush the drain with hot water in the morning. This should kill all flies and the organic material they've been feeding on.

Should I call an exterminator for drain flies?

Clean suspected drains with a commercial drain cleaner, and scrub the drain pipe vigorously with a long-handled brush. After their breeding sites have been eliminated, the reproductive cycle is disturbed. If you experience difficulty ridding your home of adult sewer flies, contact your local pest control professional.

Does Drano get rid of drain flies?

If your drain fly issue persists, consider using commercial drain cleaners such as Drano. These solutions are formulated to clear out the drains and pipes effectively, removing any debris that might serve as a breeding spot for drain flies. Using these products can aid in preventing new eggs from hatching.

How to find out where drain flies are coming from?

Drain flies feed on filth and scum that can build up in areas such as drains, drain openings, sewers, septic tanks, and kitchen sinks. A great way to identify which drain-source the flies are coming from is to put clear tape over the drain so that they will fly into it and get stuck.

How do you tell if you have a sewage problem?

Signs of Septic System Failure
  1. Water and sewage from toilets, drains, and sinks are backing up into the home.
  2. Bathtubs, showers, and sinks drain very slowly.
  3. Gurgling sounds in the plumbing system.
  4. Standing water or damp spots near the septic tank or drainfield.
  5. Bad odors around the septic tank or drainfield.

How long does a drain fly infestation last?

Learn the Pest Biology

Knowing the life cycle helps you fight fly infestations. Life Cycle: Adult females lay 30–100 eggs in sludge around sewage and drainage areas. Eggs hatch in 32–48 hours, larval stage lasts 8–24 days, pupal stage 20–40 hours. Adults live about two weeks.

Do drain flies always mean a leak?

An ongoing or recurring infestation, despite careful sanitation of all drains, can indicate a broken pipe or leak under a slab or in a crawlspace beneath the home.

Can drain flies get past a P-trap?

A dried-out p-trap allows for flies to access the drain through rooftop vent traps.

Does pouring boiling water down the drain help with gnats?

Clean Your Drain

Boiling Water: Pour boiling water down your drains to wash away gnats and their eggs. Baking Soda Solutions: Use a mixture of salt, baking soda, and white vinegar to foam away bacteria in your pipes. Chemical Cleaners: For intense infestations, consider using a chemical cleaner like Drano.

How much does it cost to get rid of drain flies?

The average cost for drain fly pest control services is $200. However, the price can range from as low as $100 to $500 in some cases, depending on the severity of the infestation and the size of the area that needs to be treated.

Can drain flies come up through a toilet bowl?

Drain flies are most often the result of a drain or sewer clog, one that limits the flow of wastewater. Unused toilets, refrigerator drains and leaking pipes can also cause them. As we previously mentioned, these insects thrive in stagnant water.

How do I get rid of drain flies forever?

Boil a pot of water and pour it down the drain where you suspect the drain flies are breeding. Pour a 1/2 cup of baking soda down the drain. Slowly pour a 1/2 cup of vinegar down the drain. Cover the drain with a drain plug, and let it sit for at least 5 to 10 minutes.

Why is my house infested with drain flies?

Trapped Sewage

Trapped waste that is part of a clog in your drain pipe is also what causes drain flies to infiltrate your home. They love sewage and will look to inhabit and reproduce inside your pipe. This is another reason why it's crucial to deal with clogged drains immediately.

Are drain flies seasonal?

Drain Flies are seasonal and you'll notice them in the spring... or not! Biochem Environmental Solutions Inc.

What smell do drain flies hate?

Peppermint, eucalyptus, and tea tree oils are especially beneficial. Pour a few drops of the chosen oil with water down the toilet. The oils' pungent aroma repels drain flies and disturbs their breeding cycle. To keep the solution effective, reapply it every few days.

Does pouring bleach down the drain get rid of drain flies?

The simple answer is yes but with a caveat. While bleach can kill drain flies and their larvae on contact, it's not the most effective method for long-term control. Bleach's caustic nature allows it to clean the drain pipes and kill some of the larvae.

What is the best product to get rid of drain flies?

Vinegar and baking soda: Pour 1/2 cup baking soda and 1 cup of vinegar down the drain.

How do plumbers get rid of drain flies?

HydroScrub® Jetting is one of the most effective professional cleaning services available today. This system uses highly pressurized water—we're talking around 3,500 PSI—to blast all debris within your pipes into the city's main sewer line.

What's the difference between drain flies and sewer flies?

Drain flies, also known as moth flies or sewer flies, are small, hairy, moth-like insects measuring 2 to 5 millimetres long depending on the species. They are weak fliers and are often seen walking near breeding sites. Females lay 30 to 100 eggs in masses on the surface of breeding medium.

Previous article
What is low water irrigation?
Next article
What does it mean when a woman wears a headscarf?