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

Don’t you hate finding unwanted bugs in your kitchen or bathroom?

No matter how often you kill them, they keep coming back with more numbers. What else can you do to prevent any bugs from entering your household?

The best solution is to clean your drains. In this article, I will teach you all the tips and tricks to stop bugs coming up the drains.

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 remember the kind of bugs inhabiting your area and the right equipment necessary to exterminate them.

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

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 remember the kind of bugs inhabiting your area and the right equipment necessary to exterminate them.

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

Sewer Roaches

Cockroaches are one of the most common pests living in your drains and are very persistent. I can’t tell you how many nights I had found a roach wandering around my bathroom floor.

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 for the roaches to eat and gather around. 

The worst part is when they start to breed. When the cockroaches find a nice spot to settle, they will 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 larva.

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 are also not 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

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 files 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.

If you ignore them long enough, they will continue to hoard food, fungus, and other things needed to live before flying away to reproduce in another location.

Fruit Flies

Fruit flies are tiny and can be very persistent near 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 either and are constantly buzzing around the organic matter.

If you keep a spotless kitchen but still see fruit flies, they are living in your garbage disposal and will need to disperse.

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 fungus and wet soil, which is why they make space near house plants. Because of their size, it becomes hard to locate them all, giving them enough 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 Come Up Drains?

Now that the common types of drain bugs are listed, it’s time to question why they decide to live in our pipes.

After dealing with my fair share of pests, I learned the same patterns that often attract bugs into my drain.

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 backup contain small residues of decomposing material and fungi growing. It only takes one bug to become attracted to the pheromones 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.

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

Don’t wait too long to do something and call a professional if the problem seems much more than anticipated.

How Do You Stop Bugs From Coming Up the Drain?

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

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 salt and pouring it down the drain. The chemicals will disintegrate all the gunk and slime for the next 24 hours, and 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.

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 in protecting your drain. Not only will it keep pests away from coming up, but it can prevent hair or 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 baby cockroaches to crawl through those openings. 

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 their mechanisms for opening and closing, so choose one that feels easy and not too complicated.

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 the 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 after bleach. Wait one or two days if needed, but the combination of chemicals will produce dangerous fumes.


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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


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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 the flush out the bugs and roaches living down your drain.

Buy Borax on

Verdict: How to Stop Bugs Coming Up the Drain

Taking away any food sources or 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 extreme 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: Stop Bugs Coming Up the Drain

Do you still have more questions about stopping bugs from coming up the drain? Check out these answers.