How to Get Rid Of Drain Flies in Bathroom?

Drain flies are one of those annoying pests that you can’t seem to get rid of. They love to congregate in our bathroom, making everything seem unhygienic. If you want to learn how to get rid of drain flies without calling in a professional, keep reading.

Why Are There Drain Flies In My Bathroom?


Drain flies are little insects no bigger than 5 millimeters that can usually be found near standing water. They are also known as sewer flies, filter flies, and moth flies.

Drain flies are usually taupe or gray in color, with rounded moth-like wings. Despite their name, they don’t really fly around. Instead, they move from surface to surface by hopping and jumping.

Their life span is about three weeks, and they lay new eggs approximately every 48 hours. In other words, if you don’t know how to get rid of drain flies quickly, you might have a problem.

Contrary to popular belief, drain flies aren’t attracted to dirt and feces. Instead, they simply love stagnant, shallow water, as it is a common source of their food, bacteria.

This is why showers and sinks are so appealing to them. They especially favor moist areas that aren’t used frequently.

Because of this, most of the time you can find them in your basement or workshop sink. It also isn’t uncommon to see them after you’re returned from a vacation.

Unlike fruit flies, another common household pest, they don’t really care about mundane sources food, such as fruit.

They need damp areas and bacteria that reproduce in moisture to survive. This is why you can find them even in the cleanest of homes.

With that being said, having drain flies doesn’t mean a house is unhygienic.

They aren’t dangerous, as well. Drain flies can’t bite you, and they don’t transmit any diseases harmful to humans or pets.

This, however, doesn’t mean you shouldn’t learn how to get rid of drain flies. Having them in your home is an indication that your home could use a good deep clean.

Especially if you don’t want to have any more pest insects, most of which are more harmful than drain flies!

How Do You Know If You Have a Problem with Drain Flies?


If you aren’t sure whether you have a drain flies problem or just a few stranded flies, there is a test. Find the drain closest to where you saw flies and place a piece of tape over it.

Make sure the sticky side is facing downwards! Leave the tape overnight, and come back to inspect it in the morning.

If you have any flies in your drain, during the night they would’ve tried to fly out to your bathroom. This will make them get stuck on the tape.

If you don’t notice any flies on the tape, or if you’ve only caught one, there’s no need to worry.

However, if you see a bunch of them, you should consider getting a good drain flies killer and getting to work.

Below is a guide on how to get rid of drain flies and similar pests.

How to Get Rid of Drain Flies?


With just a little effort, drain fly problems can typically disappear in about a week. All you have to give is some patience and dedication.

First off, you have to clean everything thoroughly. You can use a regular cleaning solution for the sink. Make sure to take a pipe brush and use it to wash inside and around the drain.

This will help you get rid of flies quite fast.

If you think your cleaning solution can damage the sink, you can use boiling water. Simply pour it down the drain up to two times a week. This will instantly kill most of the flies.

Another good option is to use a touchless faucet that will reduce the amount of water going around.

Then, pour this solution down the drain and leave it overnight. Tomorrow morning, pour boiling water as well to rinse everything and kill the remaining flies. Repeat this once or twice a week if necessary.

If you have a really serious infestation case, there is another way how to get rid of drain flies.

A heavy-duty alternative to previous methods is to use a strong drain cleaner. Products such as Bio-Clean or Xionlab are extremely toxic, despite not being insecticides.

They will eliminate anything that might be found inside the drain – from debris and clogs, to fly eggs. This way, you can get rid of any flies from drain.

In short, the best way to keep drain flies away is to keep your bathroom as clean as possible.

This will prevent fly eggs from hatching, and the existing flies don’t live very long anyway. In the end, you can always create a small fly trap.


Take a small dish of apple cider vinegar and cover it with plastic wrap. Then, poke small holes in the wrap. This way, flies will be able to fly in but not to fly out.

Gnats vs Drain Flies – How to Know the Difference?

Another common pest that often gets confused with drain flies is gnats. Gnats, also known as knats or nats, are a bit bigger than drain flies.

They are:

  • rarely bigger than 7 millimeters.
  •  longer bodies
  • elongated
  • transparent wings
  • compared to taupe
  • rounded wings of drain flies

Drain gnats tend to have hairs all over their body, which makes them look fuzzy.

Unlike drain flies, they can be quite a nuisance. Some gnat species can bite people and even spread diseases.

This is why you should always know how to get rid of gnats effectively.

Keep in mind that gnats are a type of insect that has various species. Some of them include fungus gnats, grass flies, buffalo gnats, and sand gnats.

How to Get Rid of Gnats in Drain Pipes


The best way to get rid of gnats is to destroy their feeding and breeding sources. To do this, first, you have to know which type of gnats you have.

As we’re talking about bathroom pests, we’ll explain to you how to get rid of gnats that live in drain pipes.

Drain gnats feed on the organic matter that can be found in our bathroom sinks.

Thankfully, they aren’t that hard to get rid of, and you can complete disinfection in just a week.

They aren’t dangerous but keep in mind that gnats lay up to 100 eggs at once.

In just a few days, your entire bathroom can be infested! If you are sure you have drain gnats, you can start working on getting rid of them.

The most certain way of getting rid of gnats in drain pipes is to eliminate any organic matter from sewers.

If you have older pipes, you likely have a clogging issue, which only makes everything worse.

To get rid of any organic matter that’s in your pipes, push a metal cleaning brush through the bathroom drain.

Move it back and forth to ensure everything is cleaned. Go as deep as possible. Don’t worry about damaging the pipe if you’re using the right equipment.

When you’re done cleaning, boil a pot of water and pour it down the drains. This will kill any remaining gnats or gnat eggs.

If this sounds like too much work or don’t have a good pipe cleaning brush, don’t worry.

Similarly to destroying drain flies, you can get rid of gnats using vinegar, baking soda, and boiling water. Another good idea is to pour vinegar into a spraying bottle and use it to clean the sink and drain.

This won’t just get rid of gnats, but it will also kill other insects that may be plaguing your home.

The final solution for persistent gnat infestations is to use bleach. Combine one cup of bleach and ten cups of water, then pour the solution down the drain.

Allow everything to sit for a couple of hours, then flush it with cold water. This method won’t clean the pipes as effectively as using vinegar and baking soda. Still, it will kill anything it touches, and gnats are no match for it. Also, this way, you’ll avoid using any harsh chemicals. Just make sure you use enough water in the solution! Otherwise, the bleach might damage your sink, and that is a costly expense.

Bottom Line

Drain flies and gnats are some of the common pests any household can get. They aren’t as dangerous as cockroaches and other insects, but they can be equally annoying.

They’ll breed in no time, so you should always kill them as soon as you can. This is why you should know how to get rid of drain flies and gnats effectively.

Of course, if all else fails, you can always contact local pest control. However, by using some of the methods above, you can save some money and time.

Drain flies aren’t hard to get rid of. Just remember to keep your bathroom squeaky clean to prevent them from reappearing.