How To Get Rid Of Drain Flies

The good news? You can get rid of drain flies and keep them from coming back. At Heritage Services, we help homeowners tackle everything from clogged drains to full-blown drain fly infestations, so we’ve seen (and smelled) it all. Here’s everything you need to know about these pesky insects and how to send them packing.

What Exactly Are Drain Flies?

A common drain fly is small—about 1/16 to 1/4 inch long—with a fuzzy body and wings that make it look moth-like. They’re not strong fliers, so you’ll often see them hovering near breeding sites rather than zooming around your kitchen like fruit flies.

Drain flies live and breed in moist areas where organic matter has built up. That means they can be found in floor drains, sink drains, septic tanks, clogged drains, leaking pipes, and even broken pipe sections hidden behind walls.

Here’s the kicker: a single drain fly can lay eggs in the thick sludge inside drain pipes. Within a few days, larvae hatch and feed on decaying organic matter, bacteria, and other gunk that collects in moist, stagnant areas. Left unchecked, you can go from spotting one or two adult flies to a full drain fly infestation in no time.

Why Do Drain Flies Show Up?

Drain flies are attracted to the same things you’d avoid: sludge, slime, and stagnant water. Here are some of the most common breeding sites:

• Floor drains with a layer of decaying organic matter
• Sink drains where food and grease have built up
• Septic tanks with damaged seals or poor maintenance
• Clogged drains that trap food particles and bacteria
• Broken pipe sections where moisture collects unseen
• Garbage cans with rotting waste and standing water
• Leaking pipes that keep walls or cabinets damp

Organic buildup, grease, and stagnant water attract drain flies by providing ideal breeding conditions.

If you’ve noticed adult flies in your bathroom, kitchen, or laundry room, there’s probably a breeding ground nearby. The real trick to getting rid of drain flies is removing that breeding site entirely.

Step 1: Confirm You Have Drain Flies

Before you start pouring boiling water or vinegar down your drains, make sure you’re dealing with drain flies and not fruit flies or gnats.

The Plastic Wrap Test:

1. Dry the area around the suspected drain.
2. Cover the drain with plastic wrap, securing it with tape.
3. Leave it overnight or for a few hours.
4. If you see small moth-like insects stuck to the underside, congratulations—you’ve confirmed the culprit.

Step 2: Start with a Simple Flush

For minor infestations, sometimes the easiest way to eliminate drain flies is to flush out their breeding ground.

• Pour boiling water down the drain—slowly, in stages—to loosen sludge and kill drain fly larvae.
• Repeat this process twice a day for a week.
• If you prefer, pour hot water instead of boiling to protect older pipes.

Boiling water can drown larvae and flush away decaying organic matter, but it’s usually not enough for heavy buildup.

Step 3: Scrub the Sludge Away

If boiling water alone doesn’t work, you’ll need a more hands-on approach.

• Use a drain brush to scrub the inside walls of the drain pipe.
• Work the brush deep into the pipe to reach the breeding ground.
• Wear gloves (trust us on this one—you don’t want direct contact with that gunk).
• Flush with hot water after scrubbing to remove loosened sludge.

This step is crucial because simply killing the adult flies doesn’t solve the problem—if the sludge remains, the eggs will hatch, and you’ll be back to square one.

Step 4: Try Home Remedies

If you’re not ready to break out the harsh chemicals, there are plenty of natural solutions for minor drain fly problems.

Baking Soda and Vinegar

• Pour 1/2 cup of baking soda and 1/2 cup of salt down the drain.
• Follow with 1/2 cup vinegar.
• Let it fizz for 15 minutes, then flush with boiling water.
• The combination of salt, baking soda, and vinegar creates a bubbling effect that helps scrub and clean the drain, removing biofilm and organic buildup that attracts drain flies. This not only helps kill drain flies but also freshens your sink drains.

Apple Cider Vinegar Trap

• Fill a small bowl with apple cider vinegar.
• Add a few drops of dish soap to break surface tension so flies drown instead of landing.
• Place near the breeding site to trap adult flies.
• Another effective trap is to coat the inside of a cup or jar with petroleum jelly and place it near the drain; adult drain flies will get stuck as they emerge.

Vegetable Oil Barrier

• Pour a thin layer of vegetable oil into a rarely used drain.
• This creates a film that suffocates larvae and eggs.

Lemon Juice

• Natural, smells great, and works as a mild disinfectant.
• Pour lemon juice down your drain after cleaning to deter new flies.

Step 5: Consider Commercial Drain Cleaners

For stubborn infestations, you may need to use drain cleaners. While harsh chemicals like bleach can kill drain flies, they’re not always the best choice for your plumbing. Instead, choose enzyme-based cleaners that break down organic matter without damaging pipes.

Pouring boiling water after an enzyme cleaner can help flush away loosened sludge. Repeat as needed until you no longer see adult flies.

Step 6: Fix the Root Cause

If drain flies keep coming back, there’s a bigger problem—something a quick home remedy can’t fix.

• Leaking pipes may be creating hidden moist areas where drain flies breed.
• Broken pipes could be trapping sludge and stagnant water out of sight.
• Septic tanks might be overdue for pumping.
• Clogged drains can turn into long-term breeding sites if not properly cleared.

This is where Heritage Services comes in. We don’t just treat the symptoms—we find and fix the source so you can eliminate drain flies for good.

Step 7: Prevent Drain Flies from Returning

Once you’ve done the hard work to get rid of drain flies, prevention is the next step.

• Run hot water through all drains daily.
• Clean sink drains and floor drains with baking soda and vinegar once a week.
• Keep garbage cans clean and dry.
• Repair leaking pipes promptly.
• Schedule regular drain inspections, especially if you’ve had problems before.

Remember, drain flies lay eggs in decaying organic matter. If you remove the food source, you remove the flies.

Identifying and Eliminating Filter Flies

Filter flies, often called drain flies, are easy to spot once you know what to look for. These tiny, moth-like insects have fuzzy bodies and large wings, and you’ll usually find them lingering near sink drains, floor drains, or any spot where water and decaying organic matter collect. Unlike fruit flies, filter flies are drawn to the gunk that builds up inside your pipes—think food scraps, grease, and other organic debris.

To eliminate filter flies, it’s crucial to target both the adult insects and their breeding grounds. Start by pouring boiling water down your drains to kill drain flies and their larvae hiding in the sludge. For a deeper clean, use a combination of baking soda and vinegar to break down organic matter inside your pipes. Let the mixture fizz, then follow up with more boiling water to flush everything away.

Don’t forget to scrub the inside of your drain pipes with a drain brush—this helps remove any decaying organic matter where filter flies lay eggs. Regularly cleaning your sink drains and floor drains, and making sure there’s no standing water, will go a long way in preventing a new infestation. By staying on top of these simple maintenance steps, you can eliminate filter flies and keep your home free from these persistent pests.

Drain Fly Removal in Commercial Facilities

Drain fly infestations can be especially troublesome in commercial facilities like restaurants, bars, and food processing areas, where food debris, grease, and standing water are common. In these environments, drain flies can quickly multiply, turning clogged drains, sink drains, and floor drains into major breeding sites.

To effectively eliminate drain flies in commercial settings, it’s essential to take a comprehensive approach. Begin by identifying all potential breeding sites—anywhere organic matter, food waste, or stagnant water might accumulate. Use drain cleaners and pour boiling water down drains to kill drain flies and flush out larvae. Scrubbing pipes with a drain brush will help remove the stubborn sludge where eggs and larvae thrive.

Addressing the root causes is just as important: fix leaking pipes, eliminate standing water, and ensure that all drains are free from clogs and organic buildup. Regular maintenance, such as scheduled cleaning of drains and pipes, is key to preventing future infestations. In cases of severe drain fly problems, professional drain cleaning services may be necessary to thoroughly eliminate breeding sites and keep your facility compliant with health standards.

By staying proactive and maintaining clean, dry drains, commercial facilities can eliminate drain flies, protect their reputation, and prevent the spread of diseases associated with these persistent pests.

When to Call Heritage Services

Here’s the truth—minor infestations can often be handled with DIY methods like boiling water, vinegar, and baking soda. But if you’ve tried everything and still have flies, the problem might be deeper in your plumbing system.

Our team at Heritage Services can:

• Locate hidden breeding sites inside your drain pipes
• Repair broken pipe sections causing stagnant water buildup
• Eliminate sludge in hard-to-reach areas with professional-grade tools
• Clear clogged drains safely without damaging your plumbing
• Inspect septic tanks for issues contributing to drain fly infestations

We’ve helped countless homeowners get rid of drain flies quickly and permanently, using proven methods that go beyond surface-level fixes.

Say Goodbye to Drain Flies

Drain flies may be small, but they’re a big indicator that your drains or pipes need attention. Whether they’re buzzing over your kitchen sink, crawling out of floor drains, or appearing near garbage cans, the key to getting rid of them is removing their breeding ground.

Start with home remedies like baking soda, vinegar, and boiling water. Use traps like apple cider vinegar with dish soap for adult flies. Scrub your drain pipes with a drain brush to remove the sludge where eggs and larvae live. And if you suspect a broken pipe, leaking pipes, or clogged drains, call in the pros.

At Heritage Services, we know how to kill drain flies, prevent drain flies from returning, and keep your plumbing healthy. From floor drains to septic tanks, we handle the dirty work so you don’t have to.

Don’t let a minor infestation turn into a major headache—contact Heritage Services today, and let’s get rid of drain flies for good.