How to Stop Bugs Coming Up the Drain | Flies, Gnats, and Roaches

Do you always seem to find unwanted bugs in your kitchen or bathroom? Are you starting to suspect they’re coming up through your sink or tub drains? Unfortunately, you might be right!

In this article, I will teach you all the tips and tricks to stop bugs coming up the drains and tell you a bit about some of the most common insects found in household pipes.

3 Methods To Stop Bugs From Coming Up Your Drains

Everyone has their methods for dealing with unwanted bugs but here is my advice that’s simple, effective, and can save you money and exterminator fees.

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1. Clean the Drain and Pipes with Drain Cleaner

Drain cleaners are usually the first action I use to get rid of any bugs living in my pipes.

My trick is mixing a cup of white vinegar with a half cup of baking soda and pouring it down the drain. The chemicals will disintegrate all the gunk and slime for the next 24 hours. After that, pour boiling water to flush away any remaining bugs.

Not only will this eliminate bugs but you can also clear out any debris or objects clogging your pipes.

2. Use Anti-Cockroach Drain Covers

When I realized my cockroaches were coming through the bathroom drain, I had to get something to cover that opening. A drain cover did just the trick.

Drain covers are very cheap and reliable for protecting open drains. Not only will they keep pests away from coming up but they can also prevent hair and other objects from clogging the pipes.

Make sure that the drain cover you choose has tiny holes. I had to replace my first cover because the holes were still wide enough for small bugs to crawl through. 

3. Use Your Shower, Bath, or Basin Plugs

If the drain covers or drain cleaners are not working, it might be time to bring out the shower plugs.

These rubber corks close off any passage between the pipes and the outside. The bath will fill while the water’s running but it will guarantee that no bugs or roaches will get through during the night when they are more active.

There are different styles of bath plugs with various mechanisms for opening and closing, so choose one that feels easy to use and fits your drain style well.

What Can You Pour Down The Drain To Kill Roaches And Bugs?

Pouring a disinfecting solvent down the drain is the quickest way to kill most bugs and roaches living down your pipes.

Here are my top 3 choices when deciding what drain cleaner to use:


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Pouring bleach down your drain is a surefire way to eliminate roaches quickly. Mixing it with lukewarm water turns it into the perfect disinfectant. 

I suggest using this as your last resort because bleach is highly corrosive and will damage your pipes with excessive use. One or two uses will be more than enough.

Also, do not use any other cleaner immediately before or after using bleach. You can unintentionally produce a toxic gas by mixing bleach with other household cleaners containing ammonia.


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Ammonia is another good disinfectant used to kill bugs. It is also water-soluble, so mixing an equal amount with water and pouring it down the drain is the ideal method.

Ammonia is also very effective against roaches. You can carry some of it inside a spray bottle for wandering roaches, and it will instantly get the job done. Buy Ammonia on

Again, never mix ammonia with products containing bleach.


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Not only can Borax kill unwanted pests but it is also a reliable cleaning product to clear your drains and remove rust.

Combining it with boiling water works well to flush out the bugs and roaches living down your drain.

Buy Borax on

What Kind Of Bugs Come Out Of Drains?

Before pulling out the traps and bleach bottles, you first need to know what kind of insects are invading your home.

Knowing the types and species helps you identify the kind of bugs inhabiting your area and the right equipment necessary to exterminate them.

I’ve made a list of the most common bugs you can expect to pop out of your drain pipes.

Sewer Roaches

Cockroaches are one of the most common pests living in drains and they’re very persistent. I can’t tell you how many nights I have found a roach wandering around my bathroom floor that I’m sure came through the sink or tub drain.

sewer roach

These bugs love to live in dark spaces, making open drains the perfect nesting ground. Many organic fungi and food particles cling to those pipes, which the roaches eat and gather around. 

The worst part is when they start to breed. When cockroaches find a nice spot to settle, they begin to reproduce and create a nesting ground within your drainage system.

If they are alive long enough, cockroaches can damage your walls and contaminate your living space with their feces and larvae.

Water Bugs

Water bugs are not the same as cockroaches. Although they might look the same, water bugs act differently from the common roach.

For starters, these bugs like swimming in the water. If you live near a lake or leave puddles of water after showering, you can expect these pests to arrive.

water bug

Water bugs can also bite you if threatened. Notoriously known as “toe biters,” these critters will take a chomp at your toes in self-defense if you invade their space.

They aren’t as persistent as roaches and prefer living outdoors near large bodies of water. But if they find a wet spot in your home, they can get there quickly by flying with their wings.

Drain Flies

According to the University of Maryland, drain flies are another common pest found near open drains. Once one finds a place to nest within the damp space, a drain fly will hatch over 100 eggs in 2 days and produce a whole swarm very fast.

drain fly

Close-up, these flies resemble moths because of their tiny wings and fuzzy bodies. Unlike moths, though, they are not able to fly. Instead, these drain flies hop from place to place.

Fruit Flies

Fruit flies are tiny and can be very persistent around kitchen drains. As the name implies, these insects gather around ripening fruit or any aging vegetable for feeding purposes.

fruit fly

Unlike most other pests, fruit flies like to lay their eggs inside a fermenting food source for the larvae to have something to feed on after birth. They rarely sleep and are constantly buzzing around the organic matter.

If you keep a spotless kitchen but still see fruit flies, they may be living and feeding in your garbage disposal.

Fungus Gnats

These gnats may look small and fragile but they can become a big problem if you don’t clean your pipes properly.

fungus gnat

Fungus gnats are attracted to mold, fungi, and wet soil, which is why they often set up camp near house plants. Because of their size, it’s hard to locate them all, giving them plenty of time to reproduce around the house.

It’s important to exterminate these flies before they settle into damp soil and become too hard to keep track of their movements.

Why Do Bugs Live In Drains?

After dealing with my fair share of pests, I’ve learned a few patterns that often attract bugs to my drains. In most cases, bugs hang out in drains because they provide a valuable food source and/or allow the pests to hide out of sight.

Unlimited Fungal Food

There’s a lot of garbage and hair follicles going down our drains, and I don’t pay much attention to it. The bugs love it, though.

Drains that clog and back up contain small residues of decomposing material and fungi. It only takes one bug to become attracted to the scent and settle down.

If these pipes remain unclean, the bugs will continuously feed off this area and form a colony under your noses.

Out of Sight, Out of Reach

Unless you know you have an infestation, you won’t be checking your pipes regularly.

Bugs enjoy living in damp, narrow spaces and have the upper hand in living out their life cycles without disturbance. It doesn’t take long for bugs to lay eggs and sprout larvae around the house.

Don’t wait too long to do something. Call a professional if the problem seems out of your control.

Final Thoughts On Keeping Household Drains Bug-Free

Taking away any food sources and cleaning out your drains every so often is the best way to prevent any bugs from coming up your drain.

If the problem continues, you need to take additional measures by using a drain cleaner or calling a professional to clear out the infestation. 

Whichever method you choose, be sure to act thoroughly. Otherwise, expect more to come back.

FAQs: Bugs In Drains