These 5 Tiny Bugs In Shower Grout Secretly Infest Your Bathroom

High dampness causes cracks to develop on bathroom floors, tiles, and shower grouts.

These cracks become the feeding and breeding grounds for many tiny bugs.

This guide reveals five tiny bugs in shower grout that spread fast if you don’t act quickly.

You’ll find out what causes these bugs in the shower grouts and bathroom floors, where they come from, and how to get rid of them.

Let’s jump in. 

Why Do You See Bugs On Shower Grout?

Let’s face it. Dampness and high levels of moisture attract bugs

And your bathroom is damp most of the time. 

Dampness makes the shower grouts weak. Cracks form on the shower grouts.

Different types of wastes like hair, foam, and nails get stuck in these cracks.

Because of that, sludge and molds develop. That slime and mold is the food for these tiny bugs that you’re about to find out.

Over time, these gaps widen. And these gaps become a perfect hiding place for many bugs.

Choked drains also play a role in attracting these bugs. Wastes that clog the drains are breeding grounds for a particular flying bug which you’ll find out in a minute. 

The worst part?

These bugs don’t confine themselves to your bathroom. 

They multiply fast. Unless you act quickly, these bugs will spread in all areas of your home in no time.

But inside your home, it all begins from places with excessive dampness.

So, places like the kitchen, basement, bathroom, and laundry room that are damp and have drains are where the infestation begins. 

One more thing that plays a significant role in keeping these bugs thriving.

Excessive water develops molds on the shower grout and the bathroom walls and floors.

These tiny bugs feed on the mold.

Fortunately, none of these tiny bugs in the shower grout pose any health risk. They don’t bite either.

There are many ways that these bugs enter homes and bathrooms.

Some of them come from your yard. Some can latch onto the things that you bring inside your home.

The ones that fly can also sneak inside your home if your neighborhood’s drainage system isn’t that good.

So, what are these tiny bugs in shower grout?

Let’s find them out.

5 Tiny Bugs In The Shower Grout That Spread Fast

  1. Psocids mites 
  2. Mold mites
  3. Drain flies or sewer flies
  4. Silverfish
  5. Worms

Let’s find out what these bugs are and how they land up in the shower grout and bathroom. 

Psocids Mites On Shower Grout And Bathroom Floor

Psocids Mites - Tiny Bugs In Shower Grout And Bathroom Floor

Psocids mites are tiny damp bugs that feed on the molds that develop on wet surfaces like shower grout and bathroom floors.

These mites, also known as grout mites, are common in poorly maintained bathrooms with water leakages.

And they don’t confine themselves only to your bathroom. Psocids mites can be anywhere in your home where there’s dampness and mold formation. 

So, places like the kitchen, basement, and laundry rooms are where you’ll find these mites most often. 

Many species of psocids mites infest a range of things, starting from stored grains like rice to books. 

The species of psocids that infest books are known as booklice or paper mites.

Psocids mites look like tiny brown or tan bugs on the shower grout and the bathroom floor.

They grow only up to half a millimeter long. Some are even smaller. 

Psocids mites have six legs with thick hind legs. If you see them under a magnifying glass, you’ll notice they resemble termites. 

Psocids mites have a well-developed mouth to scrape the molds and fungi that form on the shower grouts. However, they don’t bite or cause any harm to humans. 

These tiny mites move inside your home from outdoors. They’re always in search of damp places to live and breed. 

When the weather outdoors turns dry, or their numbers increase, psocids mites look for new food sources and shelter.

That’s the time when they move in through the thin gaps and cracks on the windows and doors.

Another way they get inside homes is by latching onto things like cardboard boxes or plant pots that you bring inside your home. 

Psocids mites breed fast, and unless you get rid of them, their numbers will shoot up within a few days. 

It takes ten days for a psocids mite larvae to become an adult.

Mold Mites On Shower Grout 

Mold mites - Tiny bugs in shower grout

Mold mites are tiny white bugs that feed on the molds that develop on damp surfaces. They can also be brownish too.

They grow only up to 0.03 mm in size. And like the psocids mites, mold mites are also common in the grouts on the bathroom floors.

Mold mites have hairy bristles on their bodies. They use the bristles as a sensory receptor to detect mate and food sources.

When it comes to eating, mold mites don’t limit themselves only to molds. They’re also pantry pests.

They’ll invade stored food in containers and jars in your kitchen pantry. 

Food that mold mites damage emits a stench. The food also looks dull and stale.

Mold mites are hard to spot with the naked eye. On top of being microscopic bugs, they’re also tiny transparent white bugs that camouflage well with shower grout.

So, it can be hard to detect them when they’re in small numbers. But when their numbers increase, their presence becomes noticeable in the form of discoloration that occurs on the hard surfaces that they infest.

Lumps of white dust, also known as mites dust, form on the surfaces that mold mites infest.

On the shower, grout mold mites look like whitish brown patches running across the gaps between the tiles.

These mites don’t bite humans. But like the dust mites, mold mites can also trigger allergic attacks in some people, especially in the elderly and children.

The hairy bristles on their bodies are responsible for the allergic symptoms.

When mold mites crawl onto your skin, the hairy bristles can cause itching and reddish welts.

These mites spread fast. It takes less than three weeks for an egg to develop into a matured mold mite ready to breed.

An adult female mold mite lays up to 300-400 eggs during her lifetime. The life span of a mold mite is between 10 and 30 days.

Mold mites can infest any damp object, including books and furniture.

These mites on the wood are also known as wood mites.

Drain Flies In Bathroom Floor Tiles And Shower Grout

Tiny black flying bugs in the basement - drain flies

Do you tiny fuzzy moth-like bugs on the bathroom floor? That’s drain flies.

Drain flies on the bathroom floor will look like tiny black specks. But on touching them, these tiny black bugs will hop off.

Drain flies in the bathroom and your home indicate one thing – your home has clogged drains.

Drain flies will feed on the wastes stuck in the shower grout. If there are molds, they’ll eat that too.

And drain flies will even lay eggs on the scum that gets deposited in the cracks on the bathroom floor and grouts.

Unlike the house flies and fruit flies, drain flies are weak fliers despite having developed wings.

They can’t fly in one direction. So, drain flies jump from one place to another in an erratic fashion. 

Some people confuse them with springtails in the bathroom, but springtails are bigger than drain flies. Their shapes are different too.

On top of that springtails are jumping bugs in your bathroom. As drain flies jump too, so many people can confuse springtails with drain flies.

Most of the time, the source of drain flies in the bathroom and home are the choked drains.

Drain flies from outdoors will fly into your home through open doors and windows.

Inside your home, drain flies will lay eggs on in the wastes that clog drains.

Those wastes are wet where the drain flies can lay their eggs.

The larvae from the eggs feed on the scum that develops on the interior of drains.

And when the larvae turn into adults, they come out of the drain holes.

That’s the reason you see adult drain flies near the drain holes of sinks, bathtubs, and toilets.

As drain flies are dampness chasing bugs, they can also sneak inside electrical appliances like dishwashers and refrigerators. 

Sights of dead drain flies and gnats frozen to death inside the fridge are not unusual when there’s massive drain fly infestation in the home.

They spread fast. If you don’t get rid of them, drain flies soon turn into an irritating nuisance inside your home.

But drain flies are harmless. They don’t bite.

However, they sit and feed on the most unhygienic wastes like food wastes and sewers.

Pathogens from these places stick with their bodies. When drain flies sit on food, they transfer these pathogens to your food.

These pathogens make humans sick. Hence, getting rid of drain flies and their sources is critical.

Silverfish In Bathroom Grout

Silverfish in bathroom

Like all the bugs in the list, silverfish are dampness chasing bugs.

Silverfish enter homes in search of dampness when the weather outdoors becomes too hot and dry for them. 

Silverfish are tiny black wingless bugs in the bathroom

Silverfish are nocturnal. So, they perform their feeding activity during the night.

During the day, silverfish hide in the dark gaps and corners of your bathroom.

Silverfish will feed on the dead insects, molds, organic wastes like hair and nails, and sludge that build up in the shower grout.

If the cracks in the shower grout are wide enough, they can even hide in them. 

Damp surfaces get molds and fungi. And you’ll find them on anything that develops molds, including books and paper.

Silverfish are tiny silvery bugs with scales on their bodies. At first look, they resemble shrimp. They’ve got two appendages at their rear ends and a pair of antennae on their head.

Their heads are broader than their abdomen. They’re one of the thin long bugs that you can find in your home.

Apart from molds, silverfish can also eat stored dry foods like grains and cereals, fabrics, paper, sugary stuff, and items rich in starch and protein.

So, you can also find them in your kitchen pantry.

A kitchen is also a perfect place for them to infest. The kitchen has both stored food and dampness that silverfish need to thrive and multiply.

However, the damage they cause isn’t massive. 

Silverfish don’t bite humans. They also don’t spread any diseases to humans and pets.

Worms On The Bathroom Grout

Tiny Worms Maggots In Shower Grout

Now there are no specific worms that infest bathrooms and shower grouts. 

These worms are the larvae of flies and beetles that infest bathrooms and homes.

If conditions permit, your bathroom floor and shower grouts can be an egg-laying place for many types of bugs like weevils, beetles, and drain flies.

And when their eggs hatch, their larvae venture out for food. 

One of the reasons for that is when the food supply for the larvae is not enough, or the adults have not laid their eggs on their food source.

So, you will see larvae crawling on the shower grouts, bathroom floor, bathtub, and even on the bathroom sinks.

If there are drain flies in your home and bathroom, then chances are the worms that you see are the larvae of the drain flies.

You’ll notice that these worms are tiny brownish or blackish, and they’re crawling slowly on the bathroom tiles and the grout. They’re scavenging on the scum sticking in the thin crevices on the grouts and tiles.

These worms can also be house flies’ larvae known as maggots. House flies also lay eggs in the cracks and gaps inside your home. And they won’t miss out on your bathroom if there are enough gaps in there.

How To Get Rid Of Tiny Bugs In The Shower Grout?

Now bugs in the shower grout and bathroom floor are a part of a bigger problem in your home. And it’s high dampness. 

If you try to get rid of these bugs without fixing the dampness in your home and bathroom, then all your efforts will come to naught.

So, let’s dive into the five steps to get rid of tiny bugs in the shower grout and bathroom floor.

Step#1 – Repair Leaking Pipes

One of the reasons for high dampness in the bathroom floor, walls, and even in your home is the leaking pipes.

Water constantly dripping out of leaky pipes in the plumbing area increases the dampness in the structure of your home. 

And as you know, dampness attracts bugs. 

So, check for any water leakages under the sinks, faucets, and the plumbing area of your bathroom.

Water leakages in the home’s foundation and places like the kitchen and basement also increase the overall dampness inside homes.

If you find any, fix them. Hire a plumber if you can’t fix the leakage on your own.

Step#2 – Clean And Unclog The Drains

As you know by now, clogged and choked drains are home to drain flies. Clogged drains are not only breeding grounds for drain flies but also roaches.

That’s why it’s pretty common to see baby roaches crawling from the bathroom and kitchen sink drains.

You can clean the drains by using a drain cleaner. Alternatively, you can also pour a mixture of boric acid (or borax) and hot water into the drains.

White vinegar mixed with hot water also does the job.

Both will kill any drain fly eggs, larvae, and even roaches hiding inside the drains.

If the drain clogging is too extreme, which is the case when bathrooms with clogged drains are lying unused for weeks and months, pour a mixture of bleach and hot water in the drains.

Bleach is a lethal pest killer. But don’t use this method often, not more than once. Bleach is corrosive. Overuse of bleach in drains can damage the drainpipes.

No matter what you choose to pour into the drains, always use a drain plug to close the drains of the bathroom floor, tub, and sinks.

That’ll stop the drain flies larvae, and the adult drain flies, to come out through the drain holes.

Remember, it’s critical to have unchoked drains allowing water flow. The wastes that clog drains are not just breeding grounds for drain flies, but also for mosquitoes.

Step#3 – Seal the Gaps And Cracks On The Grouts And The Tiles

The gaps and cracks that develop over time in the shower grouts hold a lot of debris that these bugs eat.

Seal those crevices. Use a silicone-based sealant to caulk these cracks. Silicone-based sealants are strong, waterproof, and they last for a decade.

And the best part? Bugs can’t chew through silicone-based sealants.

Loose floor tiles with the grouts between the tiles coming off need repair.

When the gaps and cracks on the bathroom floor become wider, then bugs like centipedes can hide in these gaps. 

Also, seal the cracks on the bathroom windows. 

Those cracks can be possible entry points for flies that dampness attracts.

Also, install window screens on the windows. It’ll stop the bugs from flying into your bathroom and home.

Step#4 – Get Rid Of Molds In the Bathroom Using Bleach

Getting rid of molds is essential, not just from the shower grouts but from the entire bathroom and home.


It’s because molds are the food source of many of these bugs. And when there’s no food supply for these tiny bugs, it becomes easy to get rid of them. 

Getting rid of molds can be tricky. And you’ll need professional help to do the job, especially when there’s heavy mold formation. 

However, you can do your bit to get rid of these molds.

Mix bleach and water in the ratio of 1:2 and pour the mixture into a spray bottle. Shake the mixture well and spray it on grouts and in places with molds on them.

Let the mixture sit on the molds for 10-15 minutes. Then take a sturdy bristle brush and scrub the surface. 

The molds should start to come out.

As a precaution, wear gloves and a mask while doing it. Bleach can damage your skin. You might not like the smell while doing the job.

You can also use a bleach disinfectant sprayer to get rid of molds if you don’t want to handle bleach. It’s safer and you won’t expose your skin to bleach.

Step#5 – Reduce Humidity In Your Home

Some places can be hot and humid, especially when you’re living in states like Florida. 

So, controlling the humidity inside your home is a great way to keep bugs away. And a dehumidifier does the job for you. But a dehumidifier doesn’t removes the mites and bugs in the bathroom.

Remember, high humidity and dampness in the home play a role in attracting bugs to your home. 

Rain and high humidity can make your home damp enough to attract bugs even if you don’t have a water leakage problem in your home.

So, install a dehumidifier in your home to make your home naturally repellent to these tiny bugs.

Also, as a measure to repel bugs from your home and bathroom, use some natural sprays like peppermint spray to keep these bugs away.

Bugs hate the smell of peppermint. It’s a proven effective bug repellent. 


The five tiny bugs in the shower grout are –

  1. Psocids mites
  2. Mold mites
  3. Silverfish
  4. Drain flies or Sewer flies
  5. Worms

Dampness and moisture attract these bugs in the bathroom.

Dampness also causes the formation of molds on the shower grout and the bathroom floor, walls, and ceiling.

Molds and wastes are food for these bugs. Both sustain them and draw these tiny bugs to damp floors, walls, and ceiling.

Their numbers increase fast if you don’t address the dampness issue in your home.

Clogged drains are also one of the reasons, especially for the presence of drain flies and their larvae in the shower grout and the bathroom sink.

This guide laid out the reasons for the presence of each of these bugs in more detail. It also has five steps to get rid of them.

Getting rid of these bugs is easy. With a little bit of precaution, you can eliminate these common bathroom bugs on your own without professional pest control.

You don’t need an insecticide spray to get rid of these bugs. 

However, if they’ve turned into a nuisance in your home, then you can use pyrethrin-based sprays that are effective against these bugs and flies.

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