7 Insects And Bugs That Crawl Up Your Drain (Removal Guide)

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Figuring out what creepy things are crawling up and out of your drain can be a big deal. Especially if you aren’t even sure how to deal with them! Most people want a solution, but if you can’t identify them, how do you get rid of them?

There are seven main insects and bugs that can crawl up your drain: drain flies, fungus gnats, cockroaches, fruit flies, phorid flies, psocid mites (or booklice) and Spiders. However, spiders only crawl up unused drains. To get rid of drain insects, you can pour boiling water, bleach, or a mixture of vinegar and baking soda down the drain.

These bugs make themselves known at the most inconvenient times, and while they aren’t really harmful, they’re a nuisance to have around. Taking time to learn what you are looking at and how to deal with them can make things more comfortable for you in your home. Let’s dive in a little deeper!

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Can Bugs Live In Drains?

The short answer is yes, bugs can live in drains!

They can, but not as many different kinds of bugs as you might think. More often than not, the bugs you see coming around your bathtubs and sinks have managed to make their way out of the walls.

However, there are a few types of insects that are capable of living and thriving in the damp, dark, often dirty pipes of your house

While it might be easy to think that anything you see in your bathroom is coming from the drains, that is a common misconception. More often than not there are only about seven culprits that actively live within these confines. The rest can be found squeezing out from the walls, and are attracted by the dampness of your walls rather than the drains themselves.

What Kind Of Bugs Live In Drains?

So, let’s get down to the nitty-gritty. What bugs and insects are living in your drains?

Drain Flies

Macro Photography of Drain Fly on White Floor

One of the most common pests you can find living in your drain are drain flies. Drain flies start as eggs before moving into the larva stage, thriving inside the wet, damp, fungus-filled space until they are fully developed. It’s at that point that you’ll discover them crawling up and out, then flying around your bathroom.

These are often one of the reasons you may have suddenly found flies in your bathroom, despite the room being cut off from any outside sources.

Drain flies often look more like common fruit gnats, but when magnified, they more closely resemble moths. They are fond of the moist, dark areas because they’re able to gather everything they need to mature before flying out to find a mate and starting the process all over again.

It does go a bit farther for these guys! Drain flies will normally thrive in just the drains alone, however, if you’ve got busted pipes or dirty fungus filled garbage disposals, those areas also serve as a hot breeding ground for them to live, lay eggs, and breed in, all the while eating away at the fungus.

Fungus Gnats

Closeup of fungus gnats being stuck to yellow sticky tape.

Fungus gnats are the next most common pest that you’ll find living in and around your drains. Fungus gnats look more delicate, with have long bodies and slender legs. Much like the drain fly, they love the mucus and fungus that exist in your drains when they aren’t cleaned properly.

Fungus gnats can also be found around your potted plants or other moist soil that you have in your garden. This is because they live and breed in the first two to three inches of soil. Though they are harmless, they are not pleasant to deal with. Especially if they land on your food, causing contaminates.

While it is a lot more common to find these fungus gnats in your house plants, under the right conditions and with the proper amount of organic matter to feed on these guys can find their way into your drain system!


Cockroach in the bathroom on the sink. The problem with insects

Cockroaches might just be the last thing anyone wants to talk about, especially around the dinner table (talk about bad table manners!) They are can cause harm to your walls, can pass on illness and contaminate food or other things with their feces and larva, and an infestation can be extremely expensive to deal with. 

While there are several different breeds of cockroaches, the most common roaches you’ll find around your home can and will take their place in your drains. It’s the perfect environment for them! Dark, humid, and with enough organic fungus and food particles for them to live on.

While you are far more likely to find flies and gnats coming out of your drains, it can signal a bigger problem if you find cockroaches crawling in and out, making their way through your piping system.

You can learn more about the best cockroach sprays, baits and traps here.

A common reason for cockroaches ending up in your drain is cracks in your pipe. They’ll live on and around the pipes before getting inside them, even if the environment is a perfect breeding ground. However, if there are cracks and leaks, they’ll take advantage as they are prone to do with any situation that gives them the upper hand in finding food and growing their nests.

Fruit Flies

fruit fly on lemon

Fruit flies are a common household pest, although far less detrimental than cockroaches. They are tiny, about the size of a gnat, and will normally find their way to aging fruit or vegetables that they can feed on. To make matters worse, fruit flies hardly sleep either.

The other place fruit flies find themselves in is the drains. Although they are not as common a pest to find in these sorts of spaces, the dark, humid area that is full of slime and organic fungus for them to feed on make for a pretty decent place for them to lay their eggs.

There might be a more likely culprit for a fruit fly because of what they naturally prefer to live off of, however, if you’ve eliminated all other options for their hiding place, then you might be getting them from inside your drain or garbage disposal.

Fruit flies have a short life span, similar to drain flies or fungus gnats, however they are a pain to deal with all the same. Especially since they breed rapidly and can get in your food and drinks, creating contamination that you’ll constantly be cleaning up.

If you’re interested in repelling fruit flies from your home, you can read our guide on the scents that fruit flies hate here.

Phorid Flies

picture of a wild phorid fly sitting on daisy fleabane.

Phorid Flies are often confused with fruit flies, however, they are a lot less fond of rotting, aging fruit. They have a unique hump-back shape to them, and another characteristic that helps these flies stand out from the others mentioned is the fact that they run before they start flying.

This means you’ll likely find phorid flies both flying around and crawling around in your sinks and tubs, depending on what stage of development they are in.

Out in their natural habitat, phorid flies prefer moist soil and can dig up to six feet deep to burrow, lay eggs, and eat. However, this means the sewage build-up in your drains can make for a perfect environment for them as well!

Hair, toothpaste residue, and food waste in your drain can leave them with everything they need to burrow, to lay eggs, to eat and grow and you’ll never know until you start finding them crawling out of these dark crevices.

Psocid Mites or Booklice

These little guys look like white specks once they have hatched and created colonies. They look, in fact, very similar to head lice! Psocid mites live off of mold and fungus, enjoying high humidity and darkened spaces. Pretty similar to a lot of our other guests today.

These mites can be found in other places as well, including getting into cereal, beneath wallpaper, or anywhere that is dark, humid, and full of mold for them to eat.

Luckily psocid mites pose no harm to humans. They can’t bite or spread disease, although seeing them might indicate that there are mold issues in your home

Psocid mites produce to sixty eggs per female and their life span is only around thirty days. But that many eggs at a time can mean that unless you get the infestation under control it isn’t going to take long for you to have way more on your hands than you bargained for.

Psocid mites can spread quickly and before you even realize what’s happening these will be in your hairbrush, on your towels, and just all up in your space!


Spider Crawling along a Hotel Bathroom Sink.

Compared to the other insects and bugs on this list, spiders don’t breed in drains.

In truth, spiders only enter drains that are unused or slightly used. Dark and slightly damp drains provide an excellent home for spiders. When you see a spider crawling out of your drain, it’s because they first crawled down your drain, and didn’t enter through the internal workings of your plumbing.

For instance, at my parents house. Mine and my brothers shared bathroom rarely gets used since we’ve moved out. To keep the plumbing a bit wet, my mom will go and wet the drain every so often. However, she’s often seen a spider or two crawling out from the sink.

If you’re interested in repelling spiders from your home, you can read our guide on the scents that spiders hate here.

How Do I Get Rid Of Bugs In My Drains?

Getting rid of these pests can be a pretty simple project and one that you might not even have to do much other than clean your pipes.

Remove Food Sources

The best possible way of clearing out these pests is by taking away their food source. By using a drain snake to clean up the film and fungus that grows down in your pipes, you can make sure that these pests don’t have anything to make a home in.

Fruit flies, the most common one that you may likely be seeing crawl up your drain, are attracted to certain types of foods. You can read more about the foods, fruits, & scents that fruit flies are attracted to here.

Pour Boiling Water Down The Drain

If you are needing short-term control of these pests, especially with drain flies and fungus gnats, boiling water can help lift some of the slime that collects in your pipes. This will help to keep the breeding ground loose and less friendly to those looking to lay eggs in the dank parts of your home.

Also – you can check out Green Gobbler’s Fruit Fly Drain Treatment, which works for drain flies as well! The thick citronella based gel coats the inside of your drain, covering all fruit flies, eggs, and larvae inside.

Pour Bleach Down The Drain

Caps of bleach down the drain can also help in some instances in clearing out some of the nests that might be forming down in your drains. Bleach is such a harsh chemical that it can kill eggs and larvae that might otherwise survive.

Use a Mixture of Vinegar and Baking Soda

There is also the option of vinegar and baking soda. The combination works very similar to Drain-O, the baking soda expanding to suffocate the larva and eggs while the vinegar helps to wash everything down. This is a more natural solution that can help eliminate many of these problems without having to resort to harsher chemicals.

Call a Professional

When it comes to the psocid mites, the best thing you can do is use pesticides, although you do not want to use them incorrectly in your home. It is important in this situation to control the humidity and call a professional.

There are always pesticides to consider, but keep in mind these could come with regulations depending on what state you are living in. You will want to check on that before applying any sort of chemicals to the same space where you will be touching and interacting on a day-to-day basis.

If you feel like going at them with a stronger hand is needed then you should look more heavily into this option and get professional assistance.

That’s A Wrap!

While it isn’t pleasant to find insects hanging around your sink or bathtub, each of them does a pretty neat job of clearing out fungus and mold that could be far more harmful to you if it wasn’t under control.

Most of them can’t bite or spread disease easily, but they can be gross and unsightly. You definitely don’t want them getting on your food or in your drinks! This makes it important to identify what you’re looking at. If you can identify it, there is a solution to the pests before they become a problem.

The biggest solution of all is making sure that you clean your drains properly. This includes any guards, and if it’s your garbage disposal, use the proper technique to get the gunk out of there so you aren’t constantly having to swat and swipe away at flying bugs that are more trouble than they are worth!


Sansone, C., & Minzenmayer, R. (2003). Drain Flies (Moth Flies or Filter Flies). Texas FARMER Collection.

Jacobs, S (1998). Booklice. Penn State Extension.

Speirs, N. B., Mahadik, G. A., & Thoroddsen, S. T. (2020). How drain flies manage to almost never get washed away. Scientific reports, 10(1), 1-12.

Schalau, J. (2000). Backyard Gardener – Cockroaches, November 15, 2000.

How to pest proof your home in under a day e-book by Zack DeAngelis

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 Take a look at my guide on Pest Proofing Your Home In Under a Day! I get into the nitty-gritty on the most common types of pests you’ll see on your property including BOTH insects and wildlife, along with the specific signs to look for regarding any pest you have questions about.

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