How To Stop Bugs from Coming Up the Drain: 5 Step Fix

Bugs coming up from your drain can be quite a shock, especially if they’re infesting the rest of your house. Luckily, you can get rid of many of them with just a few simple steps. 

In most cases, bugs coming out of your drain pipes is a sign you should clean the pipes. Hiring a plumber to flush your pipes is a good solution. However, there are plenty of home remedies you can take to stop bugs from coming up the drain

How to Stop Bugs from Coming Up the Drain 

Bugs normally live near enough to the top of the drain when it’s wet and there’s something to nest in. However, once there’s an infestation, even a good cleaning won’t necessarily get them out. What can you do? 

1. Clean the Drain 

Cleaning your drains can do a lot to get rid of bug and insect problems. For example, you can remove where cockroaches or beetles are nesting. That makes it harder for them to sit in the drains high enough to crawl out at night. For example, if you clean out the drain and the P-trap, they won’t have anything to sit in. How can you do so? Use a hook pipe cleaner to hook and pull out hair, debris, and anything else you can. Use a snake or auger to clean the pipes out as far as you can. Then follow up with drain declogger to remove any other buildup that you can. 

Once you’ve done that, you can go ahead and clean the drain out. Use a mixture of 1 part baking soda to 5 parts water and flush it down the affected drain. Then, follow it up with 1 part vinegar to 3 parts water. Then, dump boiling water down the drain to flush everything away. 

This combination is better for your drain than using bleach or ammonia. It’s also going to kill anything living in the drain. Most importantly, if you do remove clogs and debris, you remove nesting locations. The further down you can clean, the harder it will be for bugs to come back up the drain. 

Most importantly, you should repeat this process for every drain in the house. 

If you’re cleaning your sink drains, you can also take the P-trap apart and clean that by rinsing it out outside. You can soak it in bleach for a few minutes if you’d like to be extra sure. However, don’t leave it in bleach too long, as the harsh chemical can damage the pipes. 

2. Flush the Pipes

Flushing pipes is a good way to remove anything living in a drain. It’s also a good way to remove small clogs. And, if you do it yourself, it’s a good way to figure out if you have clogs at all. Of course, that may not be entirely pleasant if you’ve just filled all of your available sinks and tubs with water. But, you can always call a professional for a stronger flush if your home solution doesn’t work. 

First, boil water and flush it down the drains. The more the better, but 1-5 gallons per drain should be enough. 

Then, put a stopper in each drain and fill up the tub or sink.  Unplug the stoppers and allow all of the water to go down the drain all at once. If the tub or the sink takes extra time to drain, you have a pretty good idea that you might have a clog. 

If so, contacting a professional plumber is a good way to go. Flushing your plumbing professionally will flush out any insects in the pipes, which means it will be some time before your insect problem returns. 

3. Use Bleach or Ammonia (Not Highly Recommended)

If your insect problem is truly out of hand, you can temporarily kill insects in the top of the drains by dumping bleach down the drains. However, it is extremely important that you do not repeat this. Repeatedly dumping harsh chemicals such as bleach, ammonia, or even drain cleaner down the drains can greatly damage the pipes. You shouldn’t normally use a drain cleaner more than twice a year. If you do use bleach or ammonia, make sure you apply it to all of your drains. Otherwise, your insect problem may simply move from one pipe to the next. 

This is an emergency solution to temporarily stop bugs from coming up your drain, not a permanent solution. 

4. Use Drain Covers

If you’ve tried everything and the insects keep coming back, you can always switch to using drain covers. This means buying a shower or bathtub drain plug, using plugs in the kitchen sink, and inserting bathroom sink stoppers. This can be very inconvenient if you want to quickly wash your hands or rinse off a pan. However, it will stop the temporary problem of bugs coming up your drains. And, in the meantime, you can hire a plumber for a more permanent solution. 

5. Line the Pipes 

Sometimes ants and other small insects get into your pipes through cracks or tree roots. This is bad, not just because of the bugs. Cracks mean your drains are likely leaking, either into your yard or from the sewer. Having a plumber inspect the system and replace faulty tanks, seals, etc., can solve your problem for good. And, lining pipes can also provide a permanent solution. Lining pipes is essentially casting a smaller pipe inside your existing pipes – removing any seams and preventing new bugs from coming in – except from the sewer mains. 

How Do Bugs Get Into the Drain? 

Most insects get into the drain from your home. They enter the bathroom through open windows, cracks, and other entry points. Then, they crawl into the drain and breed there in the debris. Over time, you might end up with crickets, cockroaches, ants, and many other types of bugs. 

However, some bugs actually come from the drain. These normally enter through cracks in the pipe, poorly sealed spaces in the drain, or even faulty seals in the sewer itself. In very rare cases, you might get bugs like cockroaches coming up from the sewer itself. However, this is unlikely. 

Instead, most bug problems start in your home, migrate to the drain, and then continue to come back. They can live in the early areas of the drain – usually between your drains and the sewer – because there’s still enough oxygen and light for them to live. And, with plenty of debris from kitchens and toilets, they can stay alive in drains for a long time. 

5 Types of Bugs Coming out of Shower Drain 

While nearly any bug can move into your shower, some are more likely than others. These 5 common bug types are very likely to live in your drain. 

1. Cockroaches

Cockroaches normally move into drains from other parts of the home. Then, they live in the warm, damp confines of the drainpipe – occasionally coming back up into the house. The good news is that most drains will not supply enough food to support a large colony. In addition, the more you use the drain, the harder of a time the cockroach will have living in the drain. In fact, cockroaches need dry environments to lay and maintain eggs. You can almost always get rid of cockroaches by flushing the drains several times a day for a few weeks. 

2. Centipede

Centipedes almost never come up through drains. However, it is a popular myth that they do. Instead, centipedes come up through the threshold and cracks in the foundation. They’re often drawn to sinks and bathrooms because of the damp and wet environment. Therefore, cleaning your drain out won’t get rid of centipedes. However, you can seal around your bathroom to do so. For example, if you find cracks or holes in the foundation or in the seams to the walls, use a bead of caulk or silicone to fill it. This should rid you of your centipede problem. 

3. Drain Flies

Drain flies, moth flies, or sink flies are large, fluffy flies that are drawn to stagnant water. Normally, if you have them, you likely have a drain clog or stagnant water sitting around. In most cases, the solution is to pour boiling water down the affected drain. Then, you can follow up by taking an auger or plumbing snake to the drain. Flush it with vinegar, baking soda, and more boiling water to be sure. 

It’s also important to note that if your drain flies keep coming back, it could indicate that you have stagnant water somewhere else. That might be a leak in your plumbing. It might be a leak in your septic tank. It might be a particularly damp basement. Or, it might be sewage leaking into your yard from the neighbors. If you keep getting drain flies, inspect your full home to try to find the cause of the issue. 

4. Phorid Flies

Phorid flies, sometimes called humpback flies, congregate for the same reasons drain flies do. Chances are, you have a leak or another water problem. However, Phorid flies are much more difficult to get rid of than other flies. For example, if you don’t find and kill the full infestation, they will come back. That can be incredibly difficult, considering they can bore under concrete and have nests under your home. Your best option is to call a professional pest removal company. 

5. Fruit Flies 

Fruit flies are tiny, gnat-like flies that are drawn to moisture. Normally, if you have them, it means water is sitting in drains. You can flush your drains, clean them out, and use an auger to remove any clogs. The fruit flies should go away as soon as the drains are regularly dry again. However, if you have nearby houseplants, you’ll want to completely dry those out as well to kill the eggs. 


If you still have questions about pests in your drains, these related questions should help. 

Can you put boric acid down the drain? 

Borax or boric acid is safe to put down a drain. However, if you’re trying to kill roaches or other drain infestations, it likely won’t achieve what you want. Boric acid is too weak to quickly kill most pests. Instead, they’ll run away to another drain. 

Can mice climb up drain pipes? 

Mice can enter homes through drains. However, it is highly unlikely. Instead, mice are more likely to enter the drain from the home and then attempt to get back out. It’s always important to have a sieve installed over drains to prevent this kind of unwelcome visitor. However, if you do have mice in your drains, you can rid yourself of the problem by flushing the drain out. 

In rare cases, sewer rats may also come up through drain pipes. However, most drain sieves are far too small for rats to come up. Instead, they’re more likely to come up through toilets. Most mice found in the bathroom come out through the walls, through the foundation, and through the door or windows. However, they can exit into the sewer and stay there. 

Will bleach kill a roach? 

Bleach does kill roaches. However, it will also damage your drain pipes. Therefore, you should be very cautious about regularly using bleach to deal with an infestation in your drains. Boiling water will achieve the same results if the infestation is high enough. Plus, it doesn’t smell and it won’t damage your drains. If you have a frequent pest problem, you can make it a habit to dump boiling water down your drains. While this won’t rid you of every problem, it will certainly help. 

Wrapping Up

Most insect problems in drains come from buildup and debris in the upper parts of the drainage system. You can remove the problem by cleaning the drains or by having them professionally flushed. However, you should always exercise caution when using harsh chemicals like drain cleaner or bleach, as these can cause significant damage when used regularly. Good luck getting rid of your drain infestation.

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