Updated on March 17th, 2025
Silverfish, sometimes called silverfish bugs, are small, six-legged wingless creatures. They are often found scurrying about in the dark corners of homes, searching for bits of food and shelter.
During a recent trip to Ireland, I heard about a woman who had to navigate an exceptionally massive infestation of silverfish. She told Dublin Live that they were so numerous she found them in her baby’s milk, slept with a hooded jacket on because she was “afraid those things will crawl all over me,” and saw upwards of 60 a day.
Living in an apartment complex made the infestation difficult to control, as silverfish were everywhere—in the communal area downstairs, as well as in the apartments of others living in the complex.
After hearing this woman’s story, I decided to gather some of my research on silverfish and pen this post to answer a few important questions.
Are silverfish harmful?
I suppose the answer to this question depends on how you define harm. These silver-colored scaly pests can be harmful in the sense that they can wreak havoc on your lifestyle—gingerly chewing the corners of family photographs, nibbling away at your favorite novels and dragging their teeth (as they have weak jaws) along that well-worn cozy sweatshirt that you like to wear on Saturday mornings as you putter around the house with your lukewarm coffee.
In addition to damage caused by their dietary pleasures, their urine can be problematic too, staining your papers, books and fabrics yellow.
However, they are not harmful in the sense of carrying diseases. Silverfish:
- Do not carry viruses (like some flies)
- Do not carry bacteria (like ticks)
- Do not carry fungi
- Do not carry parasites (like cockroaches)
- Do not bite (like some ants)
- Do not sting (like wasps)
- Do not carry venom or other poisonous toxins (like some spiders)
- Do not suck blood (like mosquitoes)
While they don’t carry diseases, silverfish can still spread contaminants. Just as an ant walking across your picnic lunch can transfer germs from one surface to another—like your apple core—silverfish (and other insects (and all other insects) can do the same. Silverfish walk around a lot and not always in the most sanitary locations (think trash cans and public bathrooms). Thus, they can pick up germs from these locations and then transport them to your house, depositing them on food prep surfaces, around your food storage area and in your silverware drawer.
Silverfish can also cause allergic reactions, though this would only be in the case of extreme infestations. Silverfish (and firebrats), unlike other insects, molt continuously throughout their lives, passing through 45 to 60 instars (or development stages) in their lifetime: from egg to baby silverfish (a nymph) to larvae to adult. If your home isn’t vacuumed and dusted regularly, their external shell molting can become a part of your household dust. Over time, this dust may irritate those allergic to silverfish. Their scales contain a protein called tropomyosin, which can combine with other allergens and trigger reactions. Allergic reactions may include coughing, sneezing, congestion and rashes.
What do silverfish eat?
Silverfish eat starchy, carbohydrate-rich materials found in homes. Their diet includes paper products, natural fibers, adhesives and even organic debris. Because they can digest polysaccharides—complex carbohydrates like cellulose and starch—they damage books, clothing and stored food.
Common items silverfish eat
- Paper & books – Book bindings, wallpaper, photos, envelopes, cardboard and newspapers
- Fabrics & clothing – Cotton, linen, silk, rayon and starched garments
- Dry food sources – Flour, oats, cereals, pasta, rice, sugar and bread
- Natural fibers – Jute, rope and plant-based materials
- Organic debris – Mold, fungi, dead skin cells, dandruff and dust
- Other insects & byproducts – Shed exoskeletons, dead insects and insect waste
- Adhesives & glue – Wallpaper paste, bookbinding glue and starch-based adhesives
Even without access to food, silverfish can survive for months, making them a persistent household pest.
How do I get rid of silverfish?
Silverfish are one of the oldest and most primitive known insect species to still crawl our planet. Folks have been trying to get rid of them for a long, long time.
There are five ways you can get rid of silverfish in your home.
1. Reduce humidity
Silverfish live and develop in moist, humid places, needing high humidity levels to survive—typically between 75% and 95%. High-humidity areas in your home tend to be your laundry room, bathroom, basement or attic. Use a dehumidifier and make the environment uninhabitable for silverfish.
2. Vacuum frequently
Regularly vacuum your carpets, floors and upholstered furniture. Use a wand extension to get into any cracks, crevices and corners. Remember that silverfish are nocturnal and like to remain in dark, out of the way spaces during the day. By vacuuming, you can reduce the number of places they use for shelter.
3. Use Six Feet Under
Silverfish often lay their eggs in hidden, humid locations and rarely appear in the open. Using essential oils to kill silverfish is a natural, effective approach. Spray Six Feet Under Plant-Powered Insect Spray into any cracks and crevices between floorboards and baseboards to kill silverfish eggs on contact. If you have wallpaper, carefully inspect it for any peeling, as you may need to apply Six Feet Under where peeling is present, as the silverfish could be living, eating and laying eggs here.
Note: Silverfish eggs are yellow, measure about 1 millimeter in length, (which is ½ of a nickel’s height) and more elliptical than circular.
4. Use the Insect Buster
Fill the Insect Buster with Dust to Dust, a superb alternative to food-grade diatomaceous earth (DE). This fine-grain, porous powder is highly abrasive, breaking down an insect's exoskeleton and causing dehydration, which leads to death.
Dust to Dust is a plant-powered alternative to DE, delivering kill times up to 50% faster.
Tip: Using a precision applicator like the Insect Buster ensures even distribution and prevents messy, inaccurate placement, making direct application more effective.
For best results, apply a light, even layer into cracks and crevices. In humid areas, such as basements and bathrooms, distribute a thin barrier of Dust to Dust along room perimeters and entry points like windows and baseboards. Reapply as needed to maintain effectiveness. Dust to Dust is safe for use around family and pets when applied as directed.
5. Store all dry goods in airtight plastic containers
This is a simple but powerful way to get rid of silverfish and prevent them from invading your food storage areas. Seal all cereals, flours, grains, pastas, beans and dry pet food.
