Bristletail, tasseltail, fringetail – sounds kind of like a cute little trio of furry creatures in a Disney movie, doesn’t it? But as adorable as they sound, they’re actually all names for the same tiny creature you know by its more common name—silverfish.
Silverfish derive their more familiar name from their silvery scales and fishlike shape (wider at the top, then narrowing toward the tail). One or two won’t cause a tremendous amount of damage in most cases, nor do they spread disease. But multiple silverfish can mean trouble—like destruction of books, clothes, even wallpaper.
Signs of Silverfish Infestation
Silverfish eat paper and fabric products, often leaving tiny holes behind. But the most common property damage is caused by their waste. They consume protein—like leftover bits of meat or crumbs or other insects—dead or alive. Once they have eaten, they leave tiny bits of excrement. Brown streaks and stains and tiny fecal pellets left near likely food sources is the strongest indicator of a silverfish infestation.
Since silverfish molt—as many as 50 to 60 times during their lifetimes—the scaly skins they shed provide another clue to their presence and whereabouts. Actually spotting a live silverfish is difficult, as they prefer the dark and tend to disappear at the first sign of light.
Where to Look for Silverfish
Silverfish can survive for weeks without food and water, and nearly a year without food as long as a water source is nearby. They prefer areas that are cool and damp, like basements and crawlspaces. Look around water pipes and interior foundation walls. Check out your bathroom too, especially if it tends to become humid after bathing or showering. Make sure that basement windows are well-sealed and areas where pipes enter the house are plugged.
Because silverfish eat paper products, any storage areas with boxes or old newspapers are also likely hiding spots. And don’t forget—they prey on other insects, so think like a bug and look for areas where other insects are likely to be present.
As with any insect, it’s a lot easier to prevent a silverfish infestation than it is to try to clear them out once they establish themselves. Taking a few steps to eliminate hiding and breeding areas as well as cutting off sources of food and water are important steps to control them.
- First, clear out the clutter. Silverfish don’t like to be out in the open, and clutter makes it a lot easier for them to make themselves at home. Make a special effort to get rid of old papers, books, photos and magazines. Store the ones you want to keep in airtight containers that silverfish can’t enter. Caulk around trim and use spray foam to block holes where pipes pass through walls. This makes it difficult for insects of any kind to get behind walls where they like to hide.
- Reduce dampness. Silverfish tend to make basements and bathrooms their favorite nesting areas. So the next step in avoiding a silverfish infestation is to seal up pipes – not just at the joints, but with insulation designed to surround pipes to prevent condensation on the outside surfaces. Installing a dehumidifier in the basement and a fan that vents to the outside in your bathroom can significantly cut down on humidity and dampness in those areas and even in the rest of your home. Use plastic sheeting on dirt floors in crawlspaces. Make sure that any ridge vents or whirlygigs on your roof work properly to keep air flowing and let hot, humid air escape. Caulk your exterior window seams and touch up peeling paint to make a tough barrier against all types of insects. Clean your gutters so water flows away from your foundation.
- Keep food in sealed containers. Silverfish will consume an easy meal of cereal, rice, pasta, flour, sugar or other carbohydrates. Keep both human and pet food in strong containers with airtight lids to prevent silverfish from getting in.
If you have spotted silverfish in your home, start with one or more household remedies that could end the problem without hiring an exterminator.
- Strong-smelling essential oils like basil, citrus, cedar, clove, lavender and cinnamon often make potent silverfish repellents. Place some oil on a cotton ball and rub it along the base of pipes where they pass through the walls or along cracks in baseboard. Leave a few oil-soaked cotton balls under the kitchen or bathroom sink. Also mix a few drops of oil with some distilled water in a spray bottle, then spritz these and other areas regularly to drive the insects away. You can even keep a few cotton balls in your drawers and cabinets, provided any nearby food is sealed in an airtight containers so it won’t take on the taste and scent of the oil.
- Silverfish repellent products, including a fresh-smelling citrus spray for silverfish, are also available.
- Diatomaceous earth (DE) is a white powder containing fossilized remains of tiny sea creatures called diatoms. Used in some types of pool filters to keep the water clean, this nontoxic substance is also widely used as a holistic treatment for flea infestations. When silverfish come in contact with DE, their outer shells become abraded and scratched, causing them to dry out and die. You can sprinkle diatomaceous earth lightly around baseboards and other areas where silverfish are more likely to congregate.
- Boric acid is another natural alternative used in the same manner as DE.
- Although these products may be labeled as nontoxic or generally safe for areas with children and pets, it’s always best to ask your vet before using any substance or DIY approach to control insects. Boric acid, for example, can be harmful if ingested. In general, avoid areas where animals or children could come into direct contact with DE, boric acid or any pest-control substance.
Traps & Baits
Silverfish traps with boric acid are available on the market, but you can also make a simple homemade version with a glass jar, some masking tape, and a little flour or sugar. Start by making a few “trails” of masking tape on the outer wall of the jar, then put either a piece of bread or a small amount of flour or sugar in the bottom of the jar. Place it in any area where silverfish may hide. The silverfish will climb up the rough masking tape and slide into the jar without being able to climb out.
If these homemade approaches just aren’t proving effective in controlling silverfish populations, you might need a stronger product. Several silverfish pesticides are available that use DE or boric acid, as well as products that rely on synthetic pyrethroids like deltamethrin, cyfluthrin, cypermethrin, or sumithrin. As with any pesticide, it’s essential to follow the directions exactly, including wearing protective gear and only applying in the areas recommended. Most products are sprayed or injected into cracks and crevices where the darkness will help prevent them from breaking down too quickly. Residual sprays and dusts may also be used, especially in areas like basements, attics, crawlspaces, or other areas that aren’t frequently accessed or used. Remember to be patient: silverfish must come into contact with most pesticides in order for them to be effective, and that can take a week or longer.
Professional Removal and Control
Like other reclusive pests, the silverfish prefers the dark and can be especially difficult to track, trap and exterminate. They tend to live inside walls and ceilings where most homeowners can’t reach or apply pest control. This may be reason enough to contact an exterminator with experience in silverfish control.
Professional pest control solutions often use multiple approaches to achieve optimal effects, which is especially important when the source of silverfish infestations is difficult to determine or when your own efforts haven’t resolved the problem.
A single silverfish can have over 100 offspring during its lifetime. This means that a “small” silverfish problem can turn into a huge infestation in a very short period of time. With a little forethought, you can make your home inhospitable to these pests and hospitable for you and your family.