How to get rid of drain flies: 5 quick and effective methods

Trying to find how to get rid of drain flies can be a little, well.. draining. Also known as moth flies, sewer gnats, sink flies, filter flies, or sewer flies, drain flies linger around your kitchen, bathroom, or anywhere where there's stagnant water.

These small gnat-like flies thrive not only near H2O hotspots, especially near food sources and like mosquitoes, they hatch in water, living to the ripe old age of three weeks. Thankfully, getting rid of drain flies is dead easy. We'll show you how to get rid of flying insects that group around your gutter and other damp areas of the home.

1. Deep clean your sink

Your first port of call is to tackle the source of the issue: your sinks. With regular scrubbing most drain fly problems clear up in a week.  That sounds promising.

This method uses some of the best cleaning products on the market, including Pink Stuff (opens in new tab), and of course, our cleaning fave: the humble microfiber cleaning cloth (opens in new tab). The supplies used are suitable for most sink materials (including ceramic), but if you're wondering how to clean a stainless steel sink, we've got a whole guide on that too!

How to:

1. Pour a generous amount of soda crystals (opens in new tab) down the plughole and follow it with a slosh of white vinegar.
2. Once the mixture is fizzing pour a capful of disinfectant (we like Method (opens in new tab)) and leave it for five minutes.
3. Then pour a kettle full of boiling water down the sink to get rid of the soda crystals and dislodge any fat, oil, or grime in your pipes.
4. Next use your tub of Pink Stuff, wiping it all over the sink and rinsing well.
5. To finish, use a little more disinfectant around the sink itself and then wipe the whole basin with a microfiber cloth.

2. Make a homemade trap using apple cider vinegar

If you're still spotting flies around, create a simple yet effective homemade trap with apple cider vinegar and some plastic wrap or cling film (opens in new tab). Cleaning with vinegar won't leave a bad odor, and ACV is a natural way to kill these pests.

How to:

1. Fill a jar, mug, or dish with an inch of apple cider vinegar
2. Poke small holes in the plastic wrap or cling film to lure flies in but prevent them from escaping.
3. Leave out near where you're seeing them most and watch them flock to their demise.

3. Flush your pipes with boiling water

If you're already an avid sink cleaner, you might just need to concentrate your efforts on clearing those drains to combat the issue. This will prevent breeding and stop eggs from hatching.

The simplest method is to pour boiling water carefully down your drain 1-2 times a day for about a week to ensure that the flies don't return overnight if the water didn't clear all of the built-up grime. The best way to do this is either by boiling a full kettle (and carefully emptying down the basin) or, better still if you have a boiling water tap, run this for a few minutes at a time.

4. Try a salt and baking soda solution

We all know that cleaning with baking soda can be used to lift stains and brighten whites but did you know bicarb also has bug-busting properties when combined with table salt and vinegar?

This frugal tip comes from Blaze Bullock of Vinx Pest Control (opens in new tab) and is so easy to implement into your cleaning regime.

How to:

1. Using ½ cup of salt and a ½ cup of baking soda, sprinkle it in your sink and down the drain.
2. Once you’ve done that, pour a cup of vinegar down the drain. It may fizzle and foam, so be sure your sink or pipe has enough room to let out this excess.
3. Let it keep foaming overnight, then pour boiling water down it in the morning.

5. Use a drain cleaner

If the above methods didn't work, including using boiling water, to combat your drain fly issue, it's time to bring out the big guns in the form of a heavy-duty drain cleaner, like Green Gobbler Drain Clog Dissolver (opens in new tab) to really clear out those pipes.

Usually used for unblocking a sink, a professional cleaner will clean out any extra residue build-up attracting the flies. Just make sure to check if the product you choose is safe to use more than once if needed and whether it can be used in drains outside of the bathroom.

How do I permanently get rid of drain flies?

'Use a pipe brush (opens in new tab) to brush the pipe as far as you can go.' advises Bullock.

'Brushing the pipe dislodges the drain fly eggs and larvae from the pipe. Then, flush the pipe with boiling water and sanitize the pipe brush so you don’t unknowingly keep larvae around.'

How to prevent drain flies 

So you've done the hard bit and got rid of the drain flies but that's not the end of the story. Now you have to prevent them from coming back...

Paul Blackhurst, Head of Technical Academy at Rentokil (opens in new tab) Pest Control says: 'The key to preventing drain flies is to avoid pools of still water collecting containing sewage or other organic material. To ensure infestations don’t occur it’s important to keep drains as clean and dry as possible.'

'Flushing your drains out with either water or in more extreme cases, cleaning solutions on a regular basis will help deter filter flies from breeding. Aside from your drains, keep an eye out for standing water around your home. Never leave dirty mops in buckets of water and be sure you have a healthy septic system.'

What are drain flies attracted to?

Blackhurst says: 'Drain flies are attracted to stagnant water that collects organic debris such as food waste and sewage so are commonly found near kitchen and outdoor sinks, shower and bath drains, basement sinks, sewers, wet mop and buckets, and compost piles.'

Always keep an eye out for early signs of an infestation, even if you just spot a few drain flies. Taking precautionary steps to check and treat a possible problem is essential. Homemade fly traps, natural home remedies, and DIY fly control products can help to alleviate minor annoyances with flies. If these flies become a constant and persistent nuisance, you’ll need the expertise and knowledge of professional pest controllers to effectively eradicate the fly infestation.'