Silverfish may be tiny, but that doesn’t mean you should ignore their presence in your home. These small, wingless pests can damage cereals, books, clothes, wallpapers and other starchy items.
Managing these pests can be challenging. But there are several methods that homeowners can use to eliminate silverfish both inside and outside the home. While pesticides are available, they aren’t usually necessary. Instead, eliminating moisture and entry points can stop this problem at its root.
How to Identify Silverfish
Silverfish are only about 1/2 inch to 3/4 inch long and, like their name suggests, are pearl gray to silver in color. They’re often confused with firebrats, which are about the same size and shape, but will be more of a dull gray to brown color.
Silverfish have long, wingless bodies and a pair of long, slender antennae. Their bodies taper, from front to back, to three, tail-like appendages.
Silverfish thrive in areas with temperatures between 71 and 90 degrees F with humidity above 70%. Laundry rooms can usually supply an ideal environment. You can also find them crawling along pipes and openings along walls and floors. You might also see them in your bathroom tubs and sinks.
What Problems Can Silverfish Cause?
Silverfish are more of a nuisance than they are dangerous to people or homes. They don’t cause structural damage, but they can damage books and dry foods. They don’t spread disease.
Silverfish do molt frequently though, which can trigger allergies if debris and dust are allowed to build up. But this can be prevented with regular dusting and vacuuming.
What are Silverfish Attracted to?
Silverfish are attracted to moisture, like that caused by leaky pipes and water fixtures. But they are also attracted to starchy food sources. These include:
Books. Book bindings often have paste, which silverfish eat. They will also eat newspapers and magazines and care little about whether the item is limited edition. Books and magazines can also offer hiding places.
Wallpaper. Wallpaper paste is also a food source for these pests.
Old photographs. Keep photos properly stored in a covered photo album to preserve your memories and keep them away from silverfish.
Pantry items. In addition to the paste on cardboard cereal boxes, starchy items like flour and cereals are also attractive sources of food for these pests.
Dust. Dust particles contain all kinds of nutritious debris for silverfish, including dead skin cells and left over food.
How to Control Silverfish Outside
These creatures can also survive under rocks, in bird nests, leaf clutter, and under logs — anywhere that is warm and moist. To prevent them from finding sanctuary, keep your yard free of debris.
Gutters must also be kept free of debris and all cracks or crevices around the house need to be sealed to prevent insects from using them as entry points. Also check screens around windows for loose edges. When outdoor sanctuaries dry up, silverfish will move inside if they can.
How to Control Silverfish Inside
Silverfish like to live in places with high humidity. To avoid an indoor silverfish infestation, homeowners need to eliminate areas where moisture can build up, like around faulty plumbing.
Using a dehumidifier is also a good way to avoid excess moisture in areas like crawl spaces where moisture naturally accumulates. You want to maintain a humidity level below 50%. The following home remedies might also help:
Avoid leaving newspapers or mail lying around. These things provide food and a place to hide, so keep them picked up. Books and magazines that sit on the shelf should be moved around periodically — you’ll disturb silverfish if they’re present.
Clean out closets and other storage areas. Closets and other storage areas can collect dust on unused seasonal clothing and boxes, which is a source of food for silverfish. Cleaning these areas every once in a while prevents dust buildup.
Use bug traps. DIY traps can help detect and monitor infestations. Use small glass jars with masking tape around the outside. The tape will allow the insects to climb up, but the glass on the inside will prevent them from climbing out. Use bread or cereal inside the jar as bait and place traps where you suspect insects have been foraging.
Duct tape or glue traps can also be used. Just place lengths of duct tape, sticky side up, in areas you believe there is silverfish activity.
Use diatomaceous earth. This powder is an effective tool against many insects — including silverfish. While it cannot get rid of the silverfish on the spot, diatomaceous earth works by piercing the exoskeletons of insects if they eat it. Spread this powder at night, before bed, in places where you suspect silverfish activity and vacuum in the morning.
Use boric acid. Boric acid will not only kill silverfish, but it will stop eggs from hatching. Just like diatomaceous earth, boric acid should be spread at night and vacuumed in the morning to remove any traces of dead insects.
Just remember to wear a face mask when spreading the powder to avoid inhalation. It’s important to keep children and pets away from the area because it is highly toxic to humans and animals. Medical attention is needed if accidentally inhaled.
Keep dry foods securely stored. Since items like cereal and flour are normally packed in a box or bag, they’re vulnerable to silverfish. Instead, store these items in glass, plastic, or metal airtight containers. Silverfish won’t be able to get to them, but they also prevent other pests like cockroaches and rodents from contaminating food.
Install an exhaust fan in bathrooms. A high-quality exhaust fan will draw out leftover moisture from showers and baths, keeping the humidity low in these areas.
Use insecticides. Insecticides should be reserved for large infestations. Many insecticides haven’t been adequately tested for effectiveness against silverfish, though many list silverfish on the labels. And insecticide use won’t effectively treat the problem unless you also eliminate moisture problems.
Aerosol or liquid sprays containing pyrethrin and pyrethroids, like bifenthrin, cyfluthrin, tetramethrin, and phenothrin, are effective and should kill on contact. Follow label instructions carefully and avoid contaminating areas near food or water, including drains. There are also dust products available but they aren’t typically as effective as sprays.
If you have a silverfish infestation you can’t control with the above methods, call a pest control service. They can help you exterminate and offer advice for prevention.