Tiny Black Bugs in Bathroom [What Are They? How to Get Rid of Them?]

A common issue many people face is the presence of tiny black bugs in the bathroom. Even when you periodically clean your bathroom, it seems they keep coming back! What exactly are these tiny black bugs in the bathroom, and how do you get rid of them?

Usually, those tiny black bugs found in bathrooms are drain flies or sewer flies. They have wings and typically appear around drains in sinks and tubs. These small bugs can also breed inside drains and sinks if organic matter has accumulated in those areas. 

The small black bugs that you see inside your bathroom came from outside the house. They are actually seeking shelter and warmth. If they find that your house can also supply them with food and drink, they will set up a home and breed.

Read on to learn more about these small black bugs inside your bathroom, how you can identify them, how to get rid of them, and how to prevent them from invading again.

Tiny Black Bugs in Bathroom

tiny black bug in bathroom

Those tiny jumping bugs in the bathroom are usually drain or sewer flies. They can fly because they have tiny wings. These bugs usually appear around the drain in sinks and tubs. They are there because they probably have found decaying organic matter in those places that they can eat.

They came from outside your house. But went inside your house in search of warmth and shelter. Once the outside environment is no longer hazardous to them, they go out of your house again. However, when they find that there’s food inside your house that they can eat to survive, they will stay. And then they will breed fast.

Once these small black bugs find their way inside your bathroom, they will move in fast and form a large group. The conditions in your bathroom are ideal for their survival:

  • It has high humidity,
  • There are organic deposits there that they can eat, and lastly
  • That’s a good place for them to breed undisturbed.

These tiny bugs can enter your house and bathroom through air vents, windows, wall cracks, doors, and any opening. They can also use the small gaps in cables, plumbing, and electrical wires to invade your territory.

Indication of the Presence of Tiny Black Bugs in a Bathroom

Most often, the presence of these little tiny black bugs in your bathroom indicates any of the following:

  • There’s a problem with your plumbing,
  • There must be a good amount of decaying organic matter in your sink or drain that these bugs have been eating, enabling them to breed.

Drain flies can appear in huge numbers if they find a way into your bathroom and house.

Check out this article from Howchimp.com on how to get rid of black bugs in your house. Also, if the bugs appear to be white in color, here’s an article from Homecarezen.com that can help you identify and get rid of those white bugs in your home. If you see gray bugs, take a look at this post.

Identifying Tiny Black Bugs

The most common name of the bugs you see in your bathroom is drain flies or sewer flies. They can also be called filter flies or drainage moths. Though they may look dangerous, they are not really harmful to humans.


They don’t transmit infectious diseases. They usually don’t damage the wood and fabric of clothes. However, since they are coming in from and are staying in dirty places, they could carry parasites with them. Parasites are tiny creatures that you can’t see but can be dangerous to your health when touched or ingested.


Mature black bugs are about 0.2 to 0.3 inches long. They are covered with long gray hairs and have a long hairy antenna on their heads. Their long hairs give them a blurred look. You can confuse them with ordinary moths because they look very similar.

Like moths, they fly in a disoriented and random-like manner. When they are not flying, they sit with their wings covering their bodies like a protective shield. Drain flies start their lives as oblong eggs. The eggs hatch at ambient temperature within 32 to 48 hours of being laid.

Life Expectancy

Then they develop into larvae which mature within 9 to 15 days. These larvae grow into pupae and then into adults. An adult sewer fly has a life expectancy of about 2 to 3 weeks.

You can also confuse these tiny bugs in the bathroom with tiny ants. But mostly, if the bug flies, it is a drain or sewer fly. That is a tiny black bug. While they are not carriers of diseases, it is still recommended that you remove them permanently from your bathroom and your house.

Other Bugs In the Bathroom

Tiny black bugs are not the only creatures that can invade your bathroom. Other opportunistic insects and bugs can give these black small bugs a run for their money.

What are these other bugs that can find their way into your bathroom?

1. Booklice

tiny bugs in bathroom

These tiny creatures are common in bathrooms, but they are not harmful. They feed on mold and not decaying matter. You can cover them with boric acid or talcum powder to eradicate them and discourage them from staying.

2. Fungus Beetles

tiny jumping bugs in bathroom
Fungus beetle – tiny black bug

These small bugs also eat mold to survive. If your bathroom has high humidity, they will be there. If you eliminate mold in the bathroom, these bugs will go away.

3. Cockroaches

These creatures cause the most irritation in homes. They like dirty places. So, to discourage them from coming, always clean your drains, sinks, and drainage pipes.

4. Silverfish

tiny jumping bug in bathroom

These tiny creatures can cause serious allergies in humans. They also love humid environments. Mold is their favorite food. So, if you regularly remove mold in your bathroom, it will not stay.

How to Find Where These Tiny Black Bugs Come From

It is frustrating because no matter how you try to protect your house, pests will still find their way in. So, what are the places they are using to invade your territory?

Here are some of their possible entry points:

  • Exhaust fans and drier vents
  • Roof vents
  • Wall passages
  • Sidings
  • Crawl spaces
  • Portable loads
  • Exterior Foundation
  • Main entry points

How to Get Rid of Tiny Black Bugs in the Bathroom

Now, these tiny black bugs are inside your home, specifically your bathroom. What can you do to remove them?

Here are some tips on how to get rid of tiny black bugs in the bathroom:

1. Exterminate the Pesky Bugs

Removing the pesky little tiny bugs from your bathroom and window sills is the first thing that you should do. Those that you can see and those that are within your reach should be eradicated at once. There are organic insect killers, so use those. They won’t harm your lungs and your environment.

2. Clean the Bathroom Thoroughly

Once you have decimated the tiny bugs you can see, start cleaning your bathroom from floor to ceiling. Give special attention to the drain and the sink. They are the places where these pesky bugs are coming from.

Before cleaning anything, it is recommended that you first turn off the water supply going to your bathroom. You are drying your bathroom, so less water is better.

If you have a way to open the drain and the sink, do it. Inspect the insides of these places. Examine if these pests have already created a breeding ground. If there are deposits of decaying organic wastes, remove them. Then clean that spot thoroughly. That will deprive future pests of creating their hive. 

Clean the Drain, Sink, and Pipes Using a Brush

In cleaning the drain, sink, and pipes, use a brush. Open the P-trap under the sink to remove the wastes that might have already accumulated there. You can also pour the enzymatic cleaner into the pipes. This liquid will kill the bugs, eggs, and larvae that may have attached themselves to the walls of the pipes.

There is a bacterial gel that you can also use for this purpose. Your local cleaning supply store should have this product on its shelves. Pour the gel into the sink and the drain. This gel will cling to the walls of the pipes. It will dissolve all the organic waste build-ups of hair, shampoo, soap, and skin cells from the drain and the pipes. This gel will also help the sink to drain the water faster.

3. Clean and Disinfect the Trashcan

The bugs can use the bathroom trashcan as a hiding place. So, don’t forget to clean and disinfect it. Move it from its position so you can also clean the tiles where it is standing. Remember to empty this trash can regularly, so the bug won’t have any place to hide.

4. Set a Bug Trap

There is some chance that tiny brown bugs in the bathroom may have escaped your eyes. So, to ensure that no bugs will be left loitering in your bathroom, you need to set a trap. You don’t need to buy it from the store because you can do it yourself.

Mix water, vinegar, sugar, and a few drops of liquid detergent in a small bowl. Leave the bowl next to the sink or drain for about one week. The smell of the mixture will repel the tiny bugs. They won’t go near your bathroom if they smell it.

How to Prevent Tiny Bugs from Coming Back Again

If you want to prevent these tiny black bugs from invading your bathroom again, you have to make it less attractive to them. When they find that there is nothing there that they can eat and there is no place for them to breed, they will look elsewhere.

Here are some tips on how you can prevent tiny bugs from sheltering in your home:

1. Reduce Moisture

It is impossible to dry your bathroom because it is where everybody takes their bath. The best thing you can do is to keep it dry as much as possible. Reduce the amount of moisture inside it because moisture is one of the elements that attract bugs. If you install a dehumidifier inside your bathroom, it can regulate your bathroom’s moisture.

It is also a good practice to open the bathroom window (if your bathroom has one) after taking a bath. The heat from outside will absorb moisture that is still inside the bathroom and dry the room quickly.

2. Clean the Bathroom Regularly

If you clean your bathroom regularly, organic dirt will not accumulate to the extent that it can attract bugs. They will have no place to live in and no food to live on. So, schedule regular bathroom cleaning, especially the sink, the drain, and the pipes.

3. Seal Any Opening

Bugs come through the small openings in your bathroom. Inspect all sections of your bathroom, particularly focusing on small openings and cracks. They are the bug’s entry points. Seal all openings that you find with a suitable sealer that you can buy from the store.

4. Repair Sink and Drain Issues

Most bug problems in bathrooms are caused by sink and drain issues. This is the underlying problem of bathrooms that are infested with tiny black bugs. There are small sink and drain issues that you yourself can resolve. For bigger issues, call a qualified plumber to fix them.

5. Pour Boiling Water on the Sink and the Drain

An effective way to keep out the bugs from your sinks and drains is to pour boiling water on them once a week. This practice will keep the bugs at bay. If you have seldom used faucets, they could also be good breeding grounds for flying black bugs. To prevent this, open these faucets once or twice a week for a few minutes.

6. Use Substances That Repels Bugs

tiny black bugs in bathroom
Neem Oil

If you want to discourage these tiny black bugs from making your bathroom their haven, you should use certain substances that repel them.

Here are some of these substances that you can use inside your bathroom:

  • Neem oil – the scent of this oil is very unpleasant to small bugs
  • Peppermint oil – this oil will not only repel these pesky bugs but will also make your bathroom smell nice and wonderful.
  • Lavender oil – this oil will bring the same effects as neem oil and peppermint oil.
  • Diatomaceous earth – this substance is also a bug repellant.
  • Flypaper – you can buy this in your local store.

Conclusion: Tiny Bugs in Bathroom

Small black bugs in bathrooms are mostly drain or sewer flies. These tiny insects have wings, and they usually appear around drains in sinks and tubs. They can also breed inside these places, especially if organic wastes accumulate in them.

Getting rid of them is just the initial step. You must also take other steps to prevent them from making your bathroom their breeding place.

Again, here are some tips on how you can prevent them from coming into your house:

  1. Reduce Moisture
  2. Clean the Bathroom Regularly
  3. Seal Any Opening
  4. Repair Sink and Drain Issues
  5. Pour Boiling Water on the Sink and the Drain
  6. Use Substances That Repels Bugs

However, if you notice that there are black bugs in your house or bathroom, here are some ways on how you can get rid of them:

  1. Exterminate the Pesky Bugs
  2. Clean the Bathroom Thoroughly
  3. Clean and Disinfect the Trashcan
  4. Set a Bug Trap

Read next:

Tiny White Bugs in the Kitchen

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Baby Brown Recluse Spider: How to Identify, Is It Dangerous? [With Pictures]