8 Tiny Black Bugs In The Basement That Cause Infestation

Many homeowners don’t know or don’t believe that the basement can be a cesspool of various bugs. 

They concentrate only on getting rid of bugs in their bedroom, bathroom, kitchen, and other living spaces.

But places like basements, attics, and garages can be a source of bugs, hiding, breeding, and spreading out in all areas of your home.

In this guide, you’ll find out the most common tiny black bugs in the basement that can spread all over your home. 

You’ll learn tips and find out information on how to get rid of basement bugs. 

You’ll also find out how to make bug-proof the basement of your home.

Let’s dive in.

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Why Bugs Hide In The Basement?

Before you get into the list of tiny black bugs in the basement, let us reveal the reason for bugs infesting the basement of your home.

Knowing the reasons will help you a lot in making your basement bug-proof. You’d be able to tackle the causes of bugs in the basement and nip the bug problem at its bud.

The three reasons for bugs in the basement are –

  1. Dampness
  2. Clutter
  3. Darkness

Let’s face it. Most basements are damp. They’re underground or under the structure of your home. 

The basement walls and the floor absorb all the moisture and dampness of the rainwater. 

On top of that, add water leakages. 

That makes the basement floor damp too. 

Dampness can cause loose floors, wall fissures, and molds that provide living spaces and food to the bugs in the basement.

And when different types of basement bugs start living and breeding in the basement, it’s only a matter of time that a food chain gets established.

All basements are cluttered and dirty. No homeowner, including you, cleans the basement daily. 

Clutter and dirt attract bugs. They always had, and they always will. 

And, darkness, or lack of natural light, makes the basement a perfect place for nocturnal bugs to take refuge.

So, now that you know the reasons for bugs in the basement let’s find out the tiny black bugs in the basement you come across while you’re down there.

8 Tiny Black Bugs In The Basement

The types of basement bugs that you’re about to find out are both crawlies and flyers.

These tiny black bugs are there in most basements, especially when the basements are damp and dark.

So, here they’re.

Tiny Black Flying Bugs In The Basement – Drain Flies

Tiny black flying bugs in the basement - drain flies

Do you see buzzing tiny black bugs in the basement the moment you step in?

I bet you do.

These tiny black flying bugs in the basement are the drain flies.

There are three places in the basement drain flies originate from, live, and breed. 

These places are sump pits, basement floor drains or sinks, and breakage in sewer pipelines.

The idea of drain flies hiding and breeding in the sump pits might not come to your mind, but that’s “the” often-ignored source of drain flies in the basement.

It’s because most of the sump pit basins are fully enclosed. That hides tens of thousands of drain flies hiding and breeding in the pit.

Only a few drain flies come out from the pit, so you don’t see all the drain flies.

The reason for sump pits hiding and harboring drain flies is either a broken sump pump or the pump doesn’t trigger often.

That causes waterlogging in the sump pit. Over time, the water gets stale.

That stale water is a fertile breeding ground for drain flies, insects, and bacteria.

You don’t use basement sinks often, reasonably so.

Unused sinks cause dry floor drains.

And with debris clogging the floor drain, it is a breeding ground for drain flies and, the worse, roaches.

So, spotting drain flies on the basement, kitchen, and bathroom sinks is a regular occurrence. 

And finally, breakage in sewer pipelines causes the drain flies to live and breed in the basement.


The leakage from the sewer pipelines increases the dampness and starts to emit a nasty stench.

On top of that, if there’s a French drain type system, which you must have if there’s a sump pump and pit, then the drain flies make their way to the basement.

Other tiny black flying bugs that you’d notice in the basement are mosquitoes and house flies.

The reasons for their sightings are the same as the reasons for sightings of drain flies. 

Sow Bugs In The Basement

Tiny black bugs in the basement sow bugs

Sowbugs can easily get into the basement, especially when you’ve got a garden or yard on your property.

Outdoors, sowbugs live underneath leaf piles, underneath stones, firewoods, mulch, and any other items lying in the yard, especially where it’s moist and damp.

Sowbugs are around throughout the year. So, they can infest your basement any time of the year.

These bugs are nocturnal. So, you might not see these tiny black bugs on the basement floor during the day.

During the day, sowbugs will hide in the gaps and cracks near the damp places of your basement. In the basement, sowbugs will eat molds and other dead insects.

When the moisture or dampness levels in the basement decrease, then sow bugs die.

That’s the reason why you come across tiny black dead bugs on the basement floor, which are sowbugs when you install a dehumidifier.

Ground Beetles In The Basement

Tiny black bugs in the basement - Ground Beetle

Ground beetles are tiny black bugs that you’ll find in the basement during the summer months. Some are brown, and they enter basements through the cracks and gaps on the home’s foundation.

Growing up to ⅛ inch long, ground beetles hide under the woodpiles, leaf piles, accumulated organic debris, and stones in the outdoors.

So, why do ground beetles get inside the basement?

During summers, the soil gets dry. That leads to a decrease in dampness in the outdoors and increased heat, making the ground beetles look for a new habitat.

Also, artificial light attracts ground beetles. 

So, the light coming out of your home after the sunset attracts the ground beetles towards your home. 

Onwards to your home, ground beetles get inside the basement, looking for a cooler and damp place which the basement provides.

Ground beetles will hide in the gaps and cracks on the basement floors and walls inside the basement. 

They’ll also hide in the clutter and underneath boxes in your basement. Inside the basement, ground beetles will feed on other insects to survive.

Silverfish In The Basement

Silverfish in bathroom

Another tiny crawling bug that sneaks into the basement is the silverfish

Silverfish look like small shrimps. They’ve got a tear-shaped body, with three appendages at its rear.

On their head, there’s a pair of antennae.

From a distance, they might look black. But if you observe the silverfish closely, silverfish are either silver or brownish-black with scales on their body.

So, why do silverfish get inside the basement?

They’re one of the bugs with multiple legs that sneak inside basements in the summer months.

Silverfish are moisture-seeking bugs.

When the weather outdoors becomes hot and dry, silverfish look for damp places to live.

That’s the time when they get inside homes through the gaps and cracks on walls, window frames, and door frames.

Places like the bathroom, basement, kitchen, and laundry room are silverfish’s go-to areas inside your home.

It’s because these places are not scorching hot during the summer months and there’s high usage of water in these areas too.

Inside the basement, silverfish will feed on paper, cardboard boxes, and pieces of clothing. 

Silverfish survive on carbohydrates and cellulose, which paper and fabric provide.

Crickets In The Basement


Crickets are tiny black bugs in the basement, and home, that jump. 

Crickets, like all the bugs on the list, hide in damp and moist areas. 

On top of that, they love to hide in dark and cluttered places. 

Given the combination of all of these, your basement is an ideal place for the crickets to hide.

Crickets can eat anything.

Inside the basement, they’ll feed on pieces of clothing, paper, cardboard boxes, grease stains, and other dead insects. 

Outdoors, crickets will die during the winter months because of the cold.

But while inside the basement and in your home, crickets can survive the whole year, breeding and spreading fast.

Oriental Cockroaches In The Basement

Tiny black bugs in the basement oriental cockroach

How can’t there be cockroaches in the basement bug list!

Well, there’s one, and that’s the oriental cockroach.

Oriental roaches love damp and moist places. They’ll feed on all kinds of wet filth and dead insects. 

Water leakages, clutter, dirt, stink, and dampness, make the basement an ideal dwelling place for Oriental cockroaches.

Oriental cockroaches are black and smaller than American roaches. 

You’ll find oriental cockroaches near water leakages, drains, and on the walls in the basement. 

Feeding on wet waste makes the oriental roaches’ poop semi-liquid. 

That’s why you’d observe smear marks, which are roach feces, on the basement floors and walls. 

These roaches also nest and hide in the drains or the sump pits because they prefer to be close to wet places.

Black Spiders In The Basement

Black widow spider hiding

Spiders get into the basement because the basement has everything that a spider needs to live and thrive.

In addition to darkness, clutter, and dampness, the spider has so many bugs to eat!

As long as there are other bugs anywhere in your home and basement, your home will be a perfect place for spiders.

The spider might be on the top of the food chain in the basement. It’s because it hunts and eats all the bugs that you’ve got to know so far. 

But your basement will attract two specific types of spiders. These are the black widow spiders and the brown recluse spider. 

In addition to these spiders, clutter and lack of natural light in the basement can also invite the cobweb spider and the house spider.

Both the black widow spider and the brown recluse spider have different ways and strategies to hunt their prey. 

The brown recluse spider will wait and lurk in the gaps and corners of the basement to pounce on the prey. 

It casts its web to relax on it, not to hunt. 

The black widow spider, which is black, will make its web at the ground level to catch mostly crawling bugs.

With bugs like sowbugs, roaches, ground beetles, and silverfish, the black widow spider has enough bugs to choose from. 

Tiny Black Ants In The Basement

Carpenter Black Ant

Ants, especially carpenter ants that are black and small, can also hide in the basement. 

Like all the other bugs in the basement, these ants also like to hide in damp places. 

With so many bugs to eat, and places to hide, these ants will make nests in the different areas of the basement. 

That’s why getting rid of them in the basement can be hard and may need an intervention of an experienced pest controller because there’s no one single nest to destroy.

Other Tiny Bugs In The Basement

It’s not only the tiny black bugs that you’d find in your basement. There are other small bugs with different colors that live and hide in the basement.

With so much dampness in the basement, it’s pretty evident that there will be molds in the basements. 

And as there are molds, there’ll be bugs in the basement that feed on the molds.

Booklice is one of those mold-eating bugs that you’ll find in your basement.

Also known as psocids, booklice are tiny gray bugs in the basement.

Booklice also feeds on the paper and paper boxes that lie around in the basement.

There are many tiny brown bugs in the basement too.

Earwigs, pill bugs, stink bugs, mites, and bugs with lots of legs, like centipedes, can also sneak into the basement. 

These are moisture and darkness-seeking bugs that hide in the tight corners, gaps, and cracks. 

And finally, there can be mold mites too. 

With the presence of molds in the basement, you’ll undoubtedly come across mold mites in the basement. 

Mold mites are tiny white bugs in the basement that feed on the molds and fungi that accumulate on damp floors and walls of the basement. 

If your entire home has mold because of high moisture content, then places like the bathroom, kitchen, and laundry room can also be full of mold mites.

If you don’t get rid of mold mites fast, and don’t control the dampness of your home and basement, then the population of all these bugs will go over the roof in your basement and home. 

How To Bug-Proof Your Basement In 7 Steps?

Now that you know all the types of bugs that can inhabit your basement, it’s time to find out how to get rid of them. 

And how to stop them from entering the basement in the future.

Fix Water Leakages In The Basement To Control The Dampness In Basement

Dampness on basement floor

Till now, you might have noticed a common reason behind the presence of each bug in the basement. And that’s dampness. 

Basement, by nature, can be damp. 

It lies under the home, where it gets less natural light. 

Being close to the yard or garden, which you water often, also increases the dampness levels of the basement. 

But what about the water leakages in the basement?

The presence of these bugs shows that there must be a constant supply of moisture and dampness in the basement, which is keeping them alive. 

So, check for any plumbing defects. 

Hire a plumber to fix the water leakages. 

Check out the sump pump and sump pit. If there is waterlogging and water leakages there, fix it. 

No water leakages and leaking pipes will also lead to very little mold formation, which most of the bugs in the list feed on.

Fixing water leakage issues in the basement will solve 80% of the bug problems in the basement.

Also, make sure that there’s no water logging problem in the yard or garden, especially near the home’s foundation. 

Clean, Clean, And Clean The Basement To Remove The Clutter

All the bugs love clutter. 

These bugs hide in the clutter of your home’s basement. 

Cleaning the basement and getting rid of all the necessary junk in the basement will leave very few hiding places for the bugs in the basement. 

Use a vacuum cleaner to clean all the deep corners of the basement, especially places like under the shelves and the sink. 

If there is some furniture lying around in the basement, check for termite infestation. 

Termites can also invade your basement because they’re also moisture-seeking invasive pests.

If there is furniture that you can give away or discard, then do that. 

Wood is also a source of cellulose that can keep many of the bugs, especially termites, alive.

Ensure that cardboard boxes are free from bugs. 

Cardboard boxes are also one of the favorite hiding places for bugs.

With newspapers and old books in these boxes, it becomes a perfect hiding place for bugs like spiders, booklice, and crickets. 

As usual, discard boxes that you can do away with. 

Also, vacuum any spider webs on the ceilings and the walls. 

Pro Tip – While cleaning, always wear shoes and gloves. You don’t want any black widow spider, which may hide in the basement, to bite you.

Lay Traps To Lure The Bugs Out Of Hiding In The Basement

Many bugs can go and hide in places where you can’t reach during the cleaning and fixing of the leakage processes.

Bug traps are the best solution for them. 

There are many roach traps, and baits, and spider baits that you can use to lure these bugs out of hiding.

These traps contain poisonous material that kills the bugs and also scents that attracts them. 

But ensure that these traps are out of reach of children and pets.

Seal Any Gaps And Cracks On The Basement Walls And Floors

Cracks on basement walls

Gaps and cracks are the hiding places for bugs in the basement. And also the entry points.

Use a silicone-based sealant and a caulk gun to caulk the gaps in the basement floors and walls.

Silicone-based sealants are strong and last for at least a decade. They can easily withstand moist places, and most importantly, bugs can’t chew through them. 

Check out the plumbing areas in the basement. If there are any gaps and cracks, seal them too.

Also, check for loose flooring. 

Are there tiles coming out of the floor? If yes, then repair them. 

The ground below the loose tiles in the basement is very moist. Centipedes can easily hide underneath them. 

If the walls in the basement need repair, then do it. 

Old walls get damp fast. 

As you know, dampness in the basement is an open invitation to the bugs to sneak inside your basement.

If there are any gaps in the door frames, window frames, and furniture, seal them too.

Install A Dehumidifier In The Basement To Control The Humidity Levels In The Basement.

Dehumidifiers go a long way to reduce the moisture content in the air.

Installing a dehumidifier in the basement will keep the basement dry and make the basement bug-repelling. 

But a dehumidifier will not be effective if you don’t fix the water leakages in the basement. 

Keep Cedar Balls In The Corners Of Basement To Keep The Bugs Away

Cedar balls are effective in keeping bugs away, especially bugs like psocids and crickets. 

These balls emit a smell which bugs hate. 

You don’t have to keep many cedar balls in the basement. Only a few of them will do the job.

Keep them in the tight corners and the drawers of any basement furniture. 

If some cardboard boxes contain stuff you can’t discard, then keep a couple of cedar balls in each box.

Install Weather Strippings Wherever Possible To Deny Entry To Bugs In The Basement

All these bugs can sneak inside your home and basement through tight corners and gaps. 

So, sealing the cracks and crevices on the walls isn’t enough. 

It would be best if you do something about the gaps underneath the doors and windows to stop the bugs from exploiting these gaps.

And for that, you’ve weather stripping.

Weather strippings are a tremendous helpful accessory, yet often ignored, to keep bugs out. 

Use it on the basement door and the windows of your home.

It’ll not only block the bugs from entering your basement but also stop any bugs from sneaking inside your home.


There are eight tiny black bugs in the basement that most basements have. These are –

  1. Drain flies
  2. Sowbugs
  3. Silverfish
  4. Crickets
  5. Oriental cockroaches
  6. Carpenter ants
  7. Black widow spider
  8. Ground beetles

This guide also contains the reasons for these bugs to sneak inside the basement. 

In addition to that, there’s a seven-step guide to make your basement bug-proof. 

Remember, the key to a bug-free basement is no dampness.