Silverfish are gross: They eat stuff like books, wallpaper, and clothes, and they're hard to catch because they do it all in the dead of night. They can be found throughout the U.S. and in all types of homes—they especially love attics, basements, bathrooms, closets, crawl spaces, and laundry rooms.
These nocturnal pests rest in cracks or crevices during the day. Then they come out at night to eat your novels (they love things with glue) or your cotton sweaters (they love starchy fibers) or your pet food (they love protein), according to the National Pesticide Information Center (NPIC), a partnership between Oregon State University and the U.S. Environmental Protection Agency.
They're fast runners and good climbers. And I will try not to barf telling you that they're also laying eggs and destroying your possessions with their excrement. So how do you rid your house of a silverfish infestation?
Seal up food
You don’t want to pour a bowl of your favorite cereal just to find it’s infested with silverfish. NPIC recommends sealing dry goods—like oatmeal, pasta, rice, quinoa, flour, sugar, and pet food—in sturdy, airtight containers to prevent silverfish from reaching these tempting foods.
Reduce humidity
Silverfish thrive in moist, humid environments. Take away their favorite conditions by using a dehumidifier in a damp basement and making sure your bathroom is well ventilated.
"Keep in mind that a dehumidifier won't cure the underlying source of the humidity," says Dan DiClerico, the Good Housekeeping Institute director of the Home Improvement and Outdoor Lab who regularly evaluates home maintenance and moisture-control products. In order to address the issue, he recommends fixing leaking any pipes, sealing up any exterior cracks with caulk, and making sure your home's gutters and downspouts are channeling water away from foundation walls.
Clear clutter
If you've put off decluttering, consider this: Silverfish love hiding in—and feasting on—old books, papers, and magazines. Toss unnecessary reading material to get rid of a source of food and shelter. If you really can't bear to get rid of something, at least store it in airtight bins, especially if the paper materials will be kept in the basement or attic.
Sprinkle diatomaceous earth
Diatomaceous earth, or DE, is a crumbly white powder consisting of the fossilized remains of diatoms, a class of algae. When silverfish come in contact with DE, the fine powder destroys the insects' outer waxy coating, causing them to lose moisture and die. You can sprinkle it around your baseboards and other places you’ve seen silverfish. DiClerico recommends applying it in the evening for several nights in a row to give the nocturnal pest time to interact with it. And be sure to follow manufacturer’s guidelines, since inhaling, ingesting, or coming into contact with DE can cause irritation.
If all else fails, try a pesticide
In addition to these management strategies, you can buy small packets (like these Dekko Silverfish Paks) to poison silverfish with boric acid. Hide them in places like bookshelves, dressers, desk drawers, and under-sink cabinets as well as in the basement and attic. Silverfish feed on the substance and bring it back to other pests in the home, slowly killing them off.
But be very careful with this option if you have kids and pets in the house: Boric acid, like many pesticides, can be toxic if swallowed, according to the National Poison Control Center. Use it as a last resort, and consider talking to a professional pest management service first.
Sarah (she/her) is a deputy editor in the Good Housekeeping Institute, where she tests products and covers the best picks across kitchen, health, and food. She has been cooking professionally since 2017 and has tested kitchen appliances and gear for Family Circle as well as developed recipes and food content for Simply Recipes, Martha Stewart Omnimedia, Oxo, and Food52. She holds a certificate in professional culinary arts from the International Culinary Center (now the Institute of Culinary Education).
