Tiny Black Bugs in the Bathroom? What They Are and What to Do!

Tiny crawling or flying things in your bathroom are never pleasant to see. If you’ve found some unidentified moving spots in your bathroom, you are probably feeling worried.

What are these bugs? Are they dangerous? How do you get rid of them? This guide will help you identify and deal with the most common tiny black bugs in bathrooms. 

By far the most common black bugs found in the bathroom are drain flies, but there are a couple of other possible culprits. Here is how to identify them: 

Drain flies (Psychodidae)Tiny black flies (max 5 mm long).
On close inspection they usually have fuzzy bodies and semi-transparent wings. 
When resting, they form a characteristic shape with their winds in the form of a roof. 
Usually found around drains 
Clean your bathroom and keep the drains clean. 
Booklice (Psocids) Small, wingless insects with a prominent head. 
1-2 mm long. 
Booklice come in various colors, from white to gray. Due to the small size, they can seem like black spots against a black background. 
Usually found on walls and on moldy surfaces. 
Try to reduce humidity in your bathroom and get rid of any mold. Vacuum up the dead booklice. 
Earwigs (Forficula auricularia)Slim, long, shiny bug. Usually dark brown in color. Easily distinguishable due to characteristic pincers on the back. 
Earwigs are usually larger but can be only 5 mm long in early life stages. 
Vacuum up or otherwise get rid of any earwigs you find. Boric acid can help get rid of any you can’t catch. 

Are they dangerous?

The tiny black bugs you find in the bathroom are harmless in most cases.

Drain flies are by far the most common bathroom insects. They are usually completely harmless to humans, aside from a couple of blood-sucking tropical species that can carry various diseases. It is highly unlikely that you will find one of those in your bathroom, though. 

Booklice are actually not black, but they are really tiny and can sometimes be found on damp, moldy walls. Due to the small size they can seem black.

Booklice feed on mold and are completely harmless to humans. However, booklice can destroy books and any objects of similar consistency such as wallpapers or paintings. 

Despite popular misconceptions earwigs can’t hurt you either. Yes, they are creepy, but they are also completely harmless. The worst they could do is pinch you with their pincers, but they have no venom. 

All of this doesn’t mean that bathroom infestations should be left alone. Drain flies are quite a good indicator of filthy drains, and booklice point to mold which are definitely issues you should take care of anyway. 

How are they getting in?

How did tiny bugs get into your home? Although it might seem like they are coming from your drain, this is usually not the case.

The bug that started the infestation probably came from the outside through a window or door, but drain flies do breed inside the drains, and we usually notice them only after they have grown in numbers. 

When it comes to earwigs, there’s a high likelihood they are coming from the outside. Especially if you have a ground floor window in the bathroom, they could be coming through there.

Earwigs need a warm and damp habitat, and if the conditions outdoors become unfavorable, they might seek shelter in your bathroom. They are also incredibly nimble so they could be getting in through any tiny crack available. 

Earwigs are also commonly brought inside the house with damp objects (such as something from a damp basement or laundry) 

Booklice live wherever they find something to feed on. Since they are so tiny, they are usually brought into the home with various objects (such as an old book).

Do they come at specific times of the year?

Tiny black bugs in the bathroom can appear at any time of the year. However, they do seem to be more common during spring and summer (although this also depends on the climate you live in). 

Both drain flies and earwigs naturally breed during the summer. However, once drain flies are inside your home where it’s nice and warm, they can survive throughout the year. So don’t be too surprised if you find them in winter. 

What can you do about them?

Drain Flies 

Drain flies breed on gelatinous, slimy surfaces. The perfect habitat for them is inside a dirty drain. This is why killing the flies you see in the bathroom won’t help you. Their eggs and larvae live in the drain (or any other similar wet and slimy place they can find). 

The good news is, you can get rid of them by simply keeping your drains clean. To get rid of drain flies, you’ll simply need to clean the spot they are coming from. If it is, in fact, a drain such as in your sink or shower, you can try flushing with boiling water. 

Baking soda and vinegar can also help. First pour baking soda into the drain, then add vinegar. This will cause a foaming reaction. Wait for a couple of hours and then pour boiling water into the drain in question. You might need to do this a couple of times until the flies are gone. It’s a good idea to keep the drain covered in the meantime. 


Booklice thrive in humid environments. They are easy to eradicate – the key is creating a dry environment in your bathroom. Open the windows and keep the bathroom well ventilated. Alternatively, you can turn up the heating to dry out the air. 


Earwigs are fairly easy to eradicate as they don’t reproduce very fast. Most species only lay eggs once a year which means all you need to do is find all the earwigs already in your bathroom and kill them.

Alternatively, you can use boric acid. It is a gentle insecticide that will kill earwigs on contact. Just sprinkle some around your bathroom especially in spots where you noticed earwigs. 

Will they go away on their own?

Tiny bugs in your bathroom are not likely to go away on their own. The most common bathroom bugs, drain flies, will keep living in your drain as long as they have favorable conditions (i.e. slimy material to lay their eggs). Both drain flies and booklice love humid and warm environments and will stay as long as they have such conditions in your bathroom. 

Earwig infestations are fairly rare and they are usually brought in from the outside. It is possible that they will go away on their own but it’s definitely safer to kick them out yourself. 

How can I stop bugs from coming into my bathroom?

Drain flies can easily be prevented by keeping your drains and bathroom clean and making sure there is no stagnant water. The water can stay inside the drain pipes, which is why drain flies often appear in sinks and showers that are rarely used. Running the water every couple of days should help in preventing drain fly infestations. 

When it comes to booklice, keeping your walls dry and free of mold is the key. Earwigs usually crawl into your bathroom through some opening, so closing any cracks and keeping windows closed can help. 


Although it might seem like a scene from a horror movie, tiny black bugs in your bathroom are usually harmless. Drain flies appear often in bathrooms, especially when the space is not used frequently. Luckily, getting rid of them yourself shouldn’t be too difficult.

Below you can find advice on dealing with other bugs that might appear in your bathroom:

I’ve seen one silverfish should I be worried? 

Tiny Ants in the Bathroom? The EASY Way to Get Rid of Them

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