How to Get Rid of Drain Flies

Although not uncommon, the presence of drain flies may seem baffling. Where do they come from? Why are they in my home? Can drain flies harm my family? Like all household pests, drain flies are a nuisance, especially in large quantities. While learning the steps needed to get rid of drain flies, you also need to familiarize yourself with what drain flies are, what causes them and how to prevent a future infestation.

What Are Drain Flies?

You are probably already familiar with drain flies, even if you do not realize it. Drain flies — scientifically known as "Psychodidae" — range from 1/8 to 1/10 of an inch in size. They are broad, hairy and usually dark in color. These flies have six legs, a set of wings and antennae. Drain flies are sometimes referred to as "moth flies" or "sewage flies."

Drain flies are often found resting on kitchen or bathroom walls, near sewage drains, trash cans or septic tanks. Drain flies feed on sewage and pipe buildup. Drain flies are born with special breathing tubes that allow them to survive, even when submerged in waste.

Are Drain Flies Harmful?

Although unsettling, drain flies are usually not physically harmful, as they do not bite. However, in large quantities, drain flies could become an issue due to their tendency to block parts of plumbing pipes.

What Causes Drain Flies?

Drain fly with text about what causes Drain flies

Drain flies are attracted to still, stagnant water. If you have noticed these pests around your home, it could signify the presence of drain blockage or leaks. Drain flies enter your home in the same way regular household flies do — they squeeze through windows and drains, fly through opened doors or come up from the basement.

Drain Fly Breeding Sources

Drain flies breed and lay their eggs near the source of waste they are attracted to, including household drains and sewers. These eggs hatch after about 48 hours. After the eggs hatch into larvae, they are white and usually found inside the gelatinous part of the build-up. They stay in this membrane until adulthood. While the sight of wriggling larvae may be unnerving, they often eat away at the build-up while they are there.

Once the larvae grow into adults, they have an average lifespan of about two to three weeks. However, drain flies reproduce quickly — so once the adults' lives have ended, there will almost certainly be a new batch of larvae ready to take their place.

Steps for Getting Rid of Drain Flies

The first thing you need to do before getting rid of drain flies is locate the source. Outside, check for damaged sewage lines, the damp area beneath air conditioning units or any place that has a pool of still water. Indoors, focus your search on the areas where you see the most adult drain flies. This could be near sink and bathroom drains, toilets, showers or floor drains.

If you need help figuring out if flies are inhabiting a particular drain, you have a few options. One option is to take a clear container, line the inside with petroleum jelly and then leave it turned upside down, covering the drain. The idea is that, if the drain is home to a large number of drain flies, they will become trapped inside the jelly, confirming their presence.

After you have located the source, you may pour commercial drain cleaner down the drain, which will break down the organic material the flies are feeding on. Another way to eliminate this build-up is to use a plumbing-grade bristled brush and scrub away the membrane by hand.

Once the source has been eliminated, drain flies will leave on their own or remain until they die out. Without the organic matter to lay their eggs in, this should only take a couple of weeks at the longest.

Natural Remedies for Drain Fly Control

It is possible to get rid of lingering adult drain flies without the use of pesticides. One way is to set a trap — a bowl containing one part water, one part sugar, and one part white vinegar. Add five to eight drops of dish soap. Leave the bowl overnight, and adult drain flies should be attracted to it.

Another method is to create a do-it-yourself spray containing equal parts warm water and dish soap. Spray the adult flies as you see them.

Perhaps the most natural way to get rid of adult drain flies is to use an old-fashioned fly swatter. Although this method is usually messy to clean up afterward, it does involve zero chemicals.

How Do I Keep Drain Flies From Returning?

If you have gone through all the hard work of eliminating the source of your drain fly problem, take the necessary steps to keep them from coming back. The best way to do this is to keep your drains and plumbing as clean as possible. Do not allow gunk to build up over time. You should also do your best to eliminate any sources of stagnant water, including addressing minor leaks around the home when needed.

Should I Call a Plumber or an Exterminator?

Mr. Rooter plumber and service van

If you notice a significant amount of drain flies keep returning, no matter what you do, it is time to call a plumber. Because they thrive on sewage and plumbing buildup, a plumber might need to take a closer look at the internal parts of your plumbing to identify and eradicate the source of the infestation. Exterminators may be able to help get rid of the flies, but they are not trained to handle the more delicate parts of plumbing they may come into contact with during the process.

Drain Fly Solutions in Syracuse, New York

If you need a top-rated plumbing company to rid your home of annoying drain flies, Mr. Rooter Plumbing of Syracuse, New York is here to help. Our licensed plumbers can help you locate the source of your drain fly infestation by performing a plumbing diagnosis and inspection or by detecting leaks in your home's plumbing system.

Why Mr. Rooter Plumbing? A few reasons to consider Mr. Rooter Plumbing include:

Upfront pricing: At Mr. Rooter Plumbing, we know how important access to affordable plumbing services is. We offer up-front, flat-rate pricing that you agree to before we even begin working on your home. Our professionals will take the time to explain each necessary part of the process, giving you full knowledge and control over your plumbing.
Exceptional customer service: Our professionals pledge to leave your home as clean as we find it and are dedicated to delivering personable, respectful, and knowledgable service each and every time.
Locally owned and operated: Although Mr. Rooter Plumbing has locations all across the United States, those locations are locally owned and operated.
Licensed and insured: Each of our plumbers is licensed and insured, which is a testament to the level of knowledge and skill our plumbers have.
Workmanship parts guaranteed: Mr. Rooter Plumbing offers quality service each time, ensuring the job gets done the right way the first time.
Courteous, uniformed professionals: Our trusted professionals are instantly recognizable. Have a question? Our plumbing professionals are there to provide answers and get the job done as quickly and efficiently as possible.
Convenient appointment times: Convenient appointment times put the control back in your hands. Mr. Rooter Plumbing is committed to your convenience and offers appointment times on weekends and around the clock.