6 Reasons Why Silverfish Are Inside Your Home (What To Do)

They’re lightning fast, eat practically everything in your house, and always seem to dart out when you least expect it. Yep, we’re talking about silverfish. And anyone who’s ever dealt with these insects knows you can’t get rid of them fast enough. But why are they there in the first place?

Although there are several reasons why silverfish may be in your home, the most common causes include:

• Moisture inside your home
• Ideal living conditions outside of your home
• Dark places for the insects to hide
• Easy to access entry points
• They were brought inside
• There is something inside your home they want to eat

Luckily, fixing these things can help you control silverfish populations on your property. Join us as we take a closer look at these tiny bugs and the reasons they may be bugging you.

Silverfish Are Attracted To Damp or Humid Areas Inside Your Home

Despite what their name suggests, these wingless insects are not fish, but they do need moisture to survive.

Silverfish prefer warm moist areas and thrive in places where temperatures remain between 71° to 90°F, according to the University of California IPM. So, unless you’re like me and keep the house at a constant 65-67ish, you may have breeding grounds for silverfish in your home.

Additionally, they’re often found in bathrooms, laundry rooms, basements, kitchens, and other damp or humid places in your home.

Silverfish may also survive in drier areas if those spaces have high humidity levels. For example, while your attic may not be damp, it might be humid enough for silverfish to thrive.

According to the Norwegian Institute of Public Health, silverfish are extremely sensitive to temperature. They become much less active when temperatures drop below 60.8°F and cannot tolerate temperatures below 51.8°F or above 104°F. 

Although sharing your home with these worm-like critters can be annoying, silverfish can alert you to issues before it becomes a massive problem.

If you have silverfish in your home, you should check for the presence of leaky pipes, rotten wood, and damp areas where mold could potentially develop.

What To Do About Too Much Moisture In Your Home

It would be impossible to remove every single source of moisture from your home, but there are some things you can do to make your house less desirable to moisture-loving insects.

To control silverfish activity in your home, reduce moisture by:

• Running an air conditioner
• Using a dehumidifier
• Fixing leaky pipes
• Hanging wet laundry outside to dry
• Using fans to dry areas where water accumulates
• Running exhaust fans and opening windows while showering
• Hanging up damp towels, dishrags, washcloths, and bathmats
• Storing dirty laundry in the less humid areas of your home

Air conditioners will cut down the humidity levels inside your house. But they can sometimes cause condensation to form on windows and walls. If you use an air conditioner, keep windows and doors closed and covered.

Even a tiny leak can cause water to accumulate. Keep an eye on pipes under bathroom and kitchen sinks and make repairs as quickly as possible.

Additionally, condensation can form on pipes and fittings. Using fans and dehumidifiers can help prevent this from happening.

Use large dehumidifiers, like this 1500 Square Foot Dehumidifier, to reduce moisture throughout your home. Smaller ones, like this Ultra-Quiet 500 Square Foot Dehumidifier, can be used to target single rooms, such as bathrooms or laundry rooms.

Silverfish Like Moisture Outside Your Home Too

Like most insects, silverfish are often attracted to your yard before they ever find their way inside your home. But what attracts silverfish to your lawn?

Depending on the species, most silverfish are attracted to damp, humid areas of your lawn. You might find them:

• Under rocks
• In wood piles
• In damp mulch
• In damp leaf litter
• Under lawn debris
• Near clogged gutters
• Under the bark of fallen trees
• Around leaky spigots and faucets

Any area that offers protection, humidity, and moisture – fix it!

While some silverfish species like drier climates, the majority of house-invading species are attracted to moist areas inside and outside of your home.

How To Fix Excess Moisture Outside Your Home

You can control silverfish populations by keeping your lawn tidy and removing the damp areas the insects call home. Not only will you see fewer silverfish, but this will also help you control the populations of other moisture-loving insects such as cockroaches, earwigs, and termites.

To control silverfish activity outside your home, reduce moisture by:

• Picking up lawn debris
• Repairing leaky fixtures
• Eliminating grass clippings from your lawn
• Raking or mulching dead leaves and brush
• Keeping gutters clean to prevent overflow 
• Stacking firewood away from your house or garage
• Replacing mulch with crushed stones or cedar shavings
• Maintaining a gap between vegetation and the outside walls of your house

Grass clippings and leaves hold a lot of moisture and can become home to many insects and fungi. Using grass bags like this 21-Inch Grass Catcher Bag will prevent clumps of grass from forming on your lawn. And they can be used to pick up leaves too!

If you have a flower garden along the perimeter of your house, consider replacing the mulch (which can provide a damp cover for silverfish) with crushed stones or cedar shavings.

Crushed stone doesn’t hold moisture like mulch does, and silverfish dislike the smell of cedar. To find other scents that silverfish dislike, check out these 9 scents that silverfish hate and how to use them!

Your Home Has Several Dark Places for Silverfish to Hide

In addition to moisture, silverfish are drawn to homes that provide ample hiding places.

Silverfish are sensitive to light and prefer to remain in dark areas. They can often be found in or under:

• Basements
• Attics
• Garages
• Curtains
• Furniture
• Cardboard
• Storage boxes
• Bookshelves
• Closets
• Pantries
• Stacks of paper
• Piles of clothes

You might also find them hiding in the walls, behind baseboards, and even under wallpaper.

Silverfish are nocturnal, so homeowners don’t usually see them during the day. Many people don’t even realize they have an infestation until they move something the bugs are hiding under.

Silverfish have compound eyes that are extremely sensitive to light. They also have little sensory hairs covering their body, detecting the slightest change in air currents.

Although small, silverfish are incredibly fast. When disturbed, the tiny insects quickly dart out from wherever they’re hiding and scramble to find a new hiding place. This can make it difficult to catch or eliminate them.

What To Do About Dark Areas That Silverfish Love

Let’s be honest; removing every dark nook and cranny from your home would be impossible. So what can you do to make your space less inviting to a silverfish searching for a shady place to hide?

Since silverfish prefer hiding in dark spaces, you can make your home less inviting by:

• Keeping curtains open
• Setting silverfish traps in problematic areas
• Reducing the clutter in your home
• Utilizing scents that silverfish hate
• Using nightlights or battery-operated lights at night
• Replacing cardboard boxes with plastic storage bins

Since silverfish hate light, adding lights to areas you don’t want them to visit makes sense. Place nightlight or battery-operated lights in pantries, bathrooms, and laundry rooms to reduce silverfish activity at night.

You can also place traps in areas you believe silverfish are hiding. If you want to try this yourself, consider using these Indoor Silverfish Traps by Harris. The main goal of these is to detect silverfish, NOT fully get rid of them.

Placing sachets with scents such as citrus, cinnamon, and lavender in pantries and cupboards may deter silverfish from residing in these areas.

You can also try cutting a citrus fruit in half or using the fruit’s peels to deter the insects. Just make sure you replace the fruit every couple of days to avoid attracting fruit flies and other pests.

Finally, silverfish love clutter. Stacks of paper, piles of clothing, and messy storage areas are like vacation homes to silverfish. Remove clutter and store your stuff in airtight bins like these 20-Gallon Storage Totes from Rubbermaid.

Silverfish Like Cracks or Crevices in or Around Walls, Windows, and Doors

Despite what many people believe, silverfish don’t come in through the drains. So, how do silverfish get inside your house?

Silverfish often find their way into homes through cracks in the walls or foundation of your home. They’ll also squeeze in through gaps around windows and doors.

Silverfish are small, and most house-invading species only grow to sizes of ½ to ¾ of an inch long. On top of that, their flat body and tapered shape make it easy for them to wriggle into tiny crevices.

Silverfish typically scurry inside when living conditions become unsuitable outside. So it’s a good idea to ensure they don’t have a way into your home before taking steps to make your yard less desirable to the insects.

How To Limit Silverfish Hiding Places

There are several ways for silverfish to get inside your home. Luckily there are some things you can do to keep the critters outside. 

To pest-proof your home and keep silverfish outside:

• Fix and replace torn screens
• Ensure pet doors are secure
• Repair or replace spongy or rotted wood
• Add door sweeps to the exterior facing doors
• Add vent covers to exhaust and dryer vents
• Fill in holes around pipes, wires, and faucets
• Use caulking to plug cracks and crevices in the foundation
• Keep grass, bushes, and flowers at least a foot away from exterior walls

When filling in crevices outside your home, you’ll want to ensure you use the right product. This Silicone Caulk from Gorilla is excellent for outdoor projects because it’s waterproof and mold/mildew resistant.

Additionally – overgrown flower beds or grass give silverfish shelter and make it easy for them to scramble around, looking for a way inside. So make sure you trim any vegetation back away from your walls.

Door sweeps can be added to remove gaps beneath your exterior doors. Weatherstripping, such as this White Adhesive Weather Stripping, is a fantastic alternative because it can be cut to fit most doors.

Silverfish May Have Hitched a Ride into Your Home

If you know your house is pretty well sealed up and you’re still finding silverfish, there’s a good chance they’re being brought into the home.

Silverfish find many ways to get into your house and are often brought in on firewood or storage boxes. Additionally, silverfish eggs can be transported in clothing and contaminated food products.

Infestations typically begin in the yard before finding their way into storage sheds and garages. The insects crawl onto bikes, toys, lawnmowers, and other debris before it’s transported inside. Then they crawl off and start looking for a suitable place to hunker down.

Once silverfish invade the other buildings on your property, it’s only a matter of time before you unknowingly bring them into your house.

According to research published in Insect Biochemistry and Molecular Biology, female silverfish fertilize their eggs by picking up reproductive droppings male silverfish have dropped and left behind during mating season.

A fertilized female can lay up to 100 eggs during her life, so a silverfish infestation could theoretically begin with just one mature female.

Yikes!

Make Sure To Check Random Areas Where Silverfish Could Be

It’s important to remember that silverfish need the right environment to thrive. Controlling moisture in your home can help ensure that the ones who make it inside don’t survive.

Still, if you suspect silverfish are lurking, taking precautions to avoid an infestation is a good idea.

Keep Firewood Covered And As Dry As Possible

Silverfish love damp firewood, and because they shimmy up under the loose bark, there’s a good chance you won’t see them.

Stack firewood on racks that lift the pile off the ground. This allows air to flow under the timber, keeping it much drier. Additionally, you can cover your firewood with a tarp to keep rain from adding excess moisture.

Check Storage Boxes Thoroughly Before Bringing Them Inside

Aside from the fact that boxes of clutter make excellent hiding places, silverfish are drawn to cardboard as a source of food. Storing your stuff in plastic totes can help keep silverfish out of your things.

Soak knick-knacks and household items in bleach (when applicable) and put clothing and fabric items in the dryer on high heat (if possible). This should kill any eggs the insects might have laid.

Don’t Bring Silverfish Laden Food Into Your Home

If you’re moving from a place you know has a silverfish problem, throwing away food items high in starch or sugar is a good idea. Even if you don’t see insects, they could have laid eggs in the food.

Speaking of things that silverfish eat…

There’s Something in Your Home That Silverfish May Want To Eat

Like many insects, silverfish often enter homes when searching for food. If they find something to eat, they’ll stick around. But what do silverfish eat?

According to Colorado State University, silverfish are omnivores, which means they eat plants and animals. Because they prefer the dark, the tiny reflective insects are nocturnal and come out to feast at night.

Unfortunately, silverfish are next-level omnivores. Not only do they eat plants and animals, but they’ll also eat things made from plants or animals, such as paper or cotton products.

In the wild, silverfish eat almost anything that offers them the carbohydrates, sugars, or proteins they need to survive. This includes vegetation, grains, fungi, and even other insects. 

Once they get inside your house, almost nothing is off limits to a hungry silverfish, and they’re commonly found munching on:

• Books
• Cardboard
• Wallpaper
• Glue
• Paper products
• Pet and human hair
• Dead skin 
• Clothing
• Furniture
• Cloth items
• Carpeting
• Bedding
• Dead insects
• Fungi
• Mildew
• Foods rich in carbohydrates, sugar, or protein

Although this list is quite long, it by no means lists everything a silverfish might eat. Any clothing, paper, or food item is on this insect’s menu!

How To Limit Silverfish Food Attractants In Your Home

One of the best ways to repel a pest is to remove its food source. If the insects can’t find food, they’ll move somewhere else. But what do you do when the insect you’re trying to repel will eat almost everything in your home?

Become Vigilant About Storing Food Properly

Silverfish can chew through both paper and plastic packages. Luckily, they won’t usually chew through more durable plastic containers.

If you’re searching for a way to keep your food safe and fresh, check out this 24 Piece Pantry Organization Pack, which includes 24 containers in four sizes.

Dust And Vacuum At Least Twice A Week

This might sound extreme, but silverfish can survive just by eating the things found on your floor. Dust is made up of leftover skin, hair, fibers, and mites.

It also harbors small insects called dust mites. Keeping the nooks and crannies of your home free of dust is important when battling a silverfish infestation.

Store Bedding And Extra Clothing In Sealed Garment Bags

Silverfish will eat certain fabrics, including silk and cotton. Keep clothing and linen closets clean, dry, and tidy. Additionally, you might consider using bags like these Vacuum Storage Bags to store extra blankets and seasonal clothes.

Essential oils and satchels containing lavender and citrus scents can also be used in closets to protect clothing from silverfish.

Change Your Bedding And Clean Pet Beds Frequently

Beds contain hair and leftover skin that silverfish like to eat. Changing your sheets every few days can prevent these things from accumulating.

Pet beds should also be washed routinely, and using a removable cover will make this much easier.

Use Cedar, Mint, And Thyme To Keep Silverfish Away From Bookshelves

Because cedar naturally repels silverfish, cedar bookshelves are a great way to protect your books from damage. Additionally, you can deter these pests by placing mint leaves and thyme in places where you store books and other paper products.

Does One Silverfish Signal An Infestation?

Silverfish are nocturnal and spend their days hiding in dark, hidden places. For this reason, you might not realize you have an infestation until you notice the damage they cause or see an insect during the day.

One insect doesn’t automatically mean you have a problem. However, it’s much easier to deal with an infestation when you catch it early, so if you spot a silverfish, you should check for others nearby.

Also, if you spot a silverfish in your sink or tub, it didn’t come up through the drain. Instead, it probably fell in while searching for food and water during the night. Although this also doesn’t mean you have an infestation, it could alert you to the presence of silverfish activity in your home.

Are Silverfish Destructive To Your Home?

Although silverfish aren’t as destructive as some critters, they’re up there on the list of destructive pests.

Because silverfish eat various plant and animal products, an infestation that’s not dealt with can cause a significant amount of damage to your home and belongings.

It’s common to find silverfish damage on clothing, furniture, carpeting, and wallpaper. If left unattended, the feces and urine excreted by the insects can also cause discoloration and damage to the walls and furniture in your home.

Silverfish have several natural predators that may be lured into your home when an infestation is present. These predatory insects might also cause damage to your home.

That’s A Wrap!

There’s no doubt that silverfish are an annoying pest and one that can cause pretty significant damage to your home and belongings.

If you find yourself battling a silverfish infestation, remember to remove moisture from your home, seal any gaps around windows and doors, and keep clutter and food stored in airtight containers.

If you want more information on how you can deal with silverfish on your own, read our article on the best silverfish repellents!

You should also remember that because silverfish eggs can take several months to hatch, you might find yourself dealing with a few generations before they disappear entirely. Keeping your home free from clutter, dust, and moisture will help you get silverfish out of your home and keep them away.

References

Back, E. A. (1946). Silverfish (No. 149). US Government Printing Office.

Lindsay, E. (1940). The biology of the silverfish, Ctenolepisma longicaudata Esch. with particular reference to its feeding habits. Proceedings of the Royal Society of Victoria, 52(pt. 1). https://www.cabdirect.org/cabdirect/abstract/19410500074

Wang, S. Y., Lai, W. C., Chu, F. H., Lin, C. T., Shen, S. Y., & Chang, S. T. (2006). Essential oil from the leaves of Cryptomeria japonica acts as a silverfish (Lepisma saccharina) repellent and insecticide. Journal of Wood Science, 52(6), 522-526.

Walker, A. A., Church, J. S., Woodhead, A. L., & Sutherland, T. D. (2013). Silverfish silk is formed by entanglement of randomly coiled protein chains. Insect biochemistry and molecular biology, 43(7), 572-579.