getting rid of drain flies

What are drain flies?

Drain flies are small, dark-colored winged insects that look somewhat like moths. They're also sometimes called moth flies, filter flies, sink flies and sewer flies. Despite being winged, drain flies can't fly very far. Adult drain flies typically stay within one room instead of flying all around your home.

Drain flies come to your home, office or facility for one main reason: a food source. They feed on organic material in standing water, which is why they're attracted to drains in the first place. Wet places that have buildup food, sewage and oil residue are perfect for them. That means your kitchen sink, bathroom drains, compost piles and even septic tanks can become and ideal breeding ground for drain flies.

It's important to get rid of drain flies as soon as you can, since they can lay as many as 300 eggs in just 48 hours. Even though they only live for eight to 24 days, this rate of reproduction makes drain fly infestations likely if they aren't addressed properly.

Are drain flies harmful?

Drain flies are overall not harmful to humans, animals or the environment. They are not vectors for disease, but they can carry bacteria from their food sources to your home or facility.

The biggest issue with drain flies is that they're a nuisance. They're annoying for you, your family, employees and guests, and they make your home and facility seem gross. Especially if you're a business owner or in the tourism industry, you don't want visitors leaving your site with a memory of how bad the flies were.

kill drain flies

How to Kill Drain Flies

how to get rid of drain flies

Common Home Remedies

The absolute simplest method to address a drain fly problem is to pour boiling water down the drain. This helps wash down any organic matter that has built up in your drains, but it's not as effective for killing fly populations.

Some people also like to add a mixture of baking soda and vinegar before pouring boiling water down problematic drains. This makes the breakdown of organic material a little more effective.

Fix the Real Problem: Remove the Food Source

While clearing out drains can be helpful to get rid of drain flies, it does little to address the root of the problem: the food source.

It's more effective to eliminate the organic matter where drain flies lay eggs, the drain fly larvae live and the adult drain flies feed. Moist buildup of organic matter, known as biofilm, is the root cause of drain fly infestations. Wiping out biofilm gives drain flies no reason to live in your pipes, and kills drain flies in the process.

Pure B.S. BioSurfactant is an eco-friendly and effective solution for eliminating drain fly food sources in residential and commercial drains and pipes.

Pure B.S. Drain Fly Treatment

Stop a Drain Fly Infestation with Pure B.S.

Pure B.S. (Biological Surfactant) is an environmentally-safe and user-friendly drain treatment formulated to eliminate buildup of solids and biofilm. By eliminating biofilm, drains can be kept free of organic matter that cause clogs and odor and attract drain flies. Pure B.S. treats the source of the flies while also keeping drains flowing clearly and eliminating odors.

The base of Pure B.S. is a biological surfactant produced by Bacillus bacteria. This makes it both non-corrosive and non-hazardous. The bacteria in Pure B.S. are beneficial bacteria that outcompete the harmful bacteria that cause biofilm buildup and create a food source for drain flies. Pure B.S. is also effective on other drain-dwelling flies, like fruit flies.


It takes just 1 oz. of Pure B.S. per drain to address a drain fly issue. Let 1 oz. of the product soak. overnight and then rinse with hot water. For best results, apply to each drain once a week.

Prevent Drain Flies From Coming Back

Maintain clean drains. This can be done by applying Pure B.S. to drains on a weekly basis. This ensures that organic material does not build up and attract more flies.


If you have any questions about Pure B.S. or interest in bulk orders for commercial use, give us a call at 800-608-3755 or email We'd love to help you get rid of those drain flies!

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