Have you noticed fuzzy flies hovering around your sinks, showers, or drains? If so, you may be dealing with drain flies. These pesky insects can be a nuisance, but fortunately, they are relatively easy to eliminate. In this post, we’ll cover what drain flies are, why they appear, and the best methods to get rid of them for good.

What Are Drain Flies?

Drain flies, also referred to as moth flies or sewer flies, are small, non-biting flies. They thrive in damp, organic-rich environments, such as stagnant drain water. They are usually 1/8 inch long, fuzzy, and dark-colored. They look like moths because they have tiny hairs covering their wings. Despite their unsanitary-sounding name, drain flies do not bite or transmit diseases, but their presence can indicate underlying plumbing or hygiene issues.

Why Do Drain Flies Appear?

Drain flies lay their eggs in the organic matter that builds up inside drains, pipes, and other moist areas. Common causes of drain fly infestations include:

Clogged or dirty drains — Built-up grime, food debris, and biofilm provide the perfect breeding ground. Drain flies also love to feed on the decaying gunk in your drains, including hair, grease, and food scraps. 

Standing water — Leaky pipes, condensation, or slow-draining water can attract drain flies.

Unused drains — Stagnant water in guest bathrooms or infrequently used sinks can harbor drain flies.

Sewage or septic issues — A sewer line problem, such as a clog or leak, can create conditions where drain flies flourish.

How to Get Rid of Drain Flies

Identify the Source

The first step in eliminating drain flies is pinpointing their breeding ground. Cover suspect drains with clear tape overnight — if flies stick to the tape, you’ve found their home.

Clean the Drains

Once you’ve identified the problem area, follow these steps to clean the drains effectively:

Flush with hot water — Pour boiling water down the drain to break up organic matter. This can also kill any drain fly larvae that may be in the drain. 

Use a drain cleaner — A mixture of baking soda and vinegar can help dissolve gunk. Pour half a cup of baking soda into the drain, followed by half a cup of vinegar, wait 15-20 minutes, then rinse with boiling water. 

Scrub with a drain brush — Physically removing biofilm also ensures eggs and larvae are destroyed. You should scrub the drain once a week to prevent build-up. If you have really stubborn, stuck-on grime, the Drain X team can help blast away build-up in your drain and pipes using hydro-jetting. 

Use enzyme-based cleaners — These natural cleaners break down organic buildup without harming pipes.

Eliminate Standing Water

Fix any leaks, dry wet areas, and clean up standing water to make your home less inviting to drain flies. Besides drains, moist areas you may not think about include wet lint in your laundry room, standing water in a drain pan under your fridge, or soggy areas around house plants. 

Trap and Kill Adult Flies

To reduce the number of adult flies while addressing the root problem, try these methods:

Apple cider vinegar trap — Fill a bowl with apple cider vinegar and cover it with plastic wrap, poking holes small enough to get flies in but not escape. The flies will be attracted to the vinegar and get trapped. You can also add a small amount of dish soap to help trap flies. 

Dish soap and water spray – A mixture of dish soap and water can be sprayed directly on flies to kill them.

Sticky traps – Place sticky traps near infested drains to catch adult flies. Sticky traps come in all shapes and sizes, so you can get one that suits the area.  Make sure to replace them regularly to keep them effective. 

Prevent Future Infestations

Clean drains regularly — Flush drains with boiling water or enzyme-based cleaners weekly to prevent the build-up of debris and sludge. 

Fix leaks and moisture issues — Prevent standing water by repairing leaks and improving ventilation. Call a professional if you aren’t sure where the problem is or if you have a big leak. 

Keep drains covered — Use drain covers to reduce buildup and block fly entry. This mesh material will allow water to drain but prevent flies from entering. 

Keep Your Drains Clear of Pesky Drain Flies

If you find yourself annoyed by drain flies, don’t worry, they can be easily managed with the right approach. By cleaning your drains, eliminating moisture, and maintaining proper hygiene, you can keep these pests away for good. If the infestation persists despite your efforts, consider consulting a professional plumber to check for deeper plumbing issues.