Silverfish are wingless, soft-bodied pearl gray or silver insects that thrive in warm, humid areas inside the home. They can damage books, paper, cardboard, clothing, stored food, wallpaper and wallboard as they feed upon cellulose and carbohydrates. Controlling silverfish means making your home inhospitable to them as well as removing eggs, nymphs and adults.
Simple environmental changes can repel silverfish. Since they thrive in warm, humid areas, using dehumidifiers dries out their preferred habit. In bathrooms, running exhaust fans or opening windows to ventilate steam after baths and showers reduces humidity. Open crawl space vents for better air circulation. Caulk window openings to prevent them from slipping in through cracks. Discard infested materials such as spoiled food, old newspapers and books, or ruined clothing to remove their food sources.
Female silverfish lay anywhere from 2 to 20 eggs eggs per clutch, depending on the species. Egg often resemble common household dust, while silverfish feces look like grains of pepper. Vacuuming and dusting areas, especially dark closets and dresser drawers, removes unhatched eggs and nymphs. Inspect any purchases of used books, clothing or furniture for silverfish damage prior to bringing them into your home; damage indicates the potential for eggs. Vacuum used furniture and wash clothing in hot water to remove eggs.
Cinnamon is often cited as a home remedy for silverfish, but it has variable results. It tends to repel silverfish but doesn't kill them. Many people use cinnamon in kitchen areas to repel silverfish and add a pleasant scent. Texas A&M recommends clove or thyme oil. Diatomaceous earth, a natural powder found in garden centers, may also be used inside the home. It's made from ground diatoms, or tiny fossilized crustaceans, and the sharp points cut into the soft-bodied silverfish to kill them without harming the environment.
There are several commercial pesticides available over the counter that kill silverfish adults, nymphs and eggs. Sticky traps similar to those used to control cockroaches also work on silverfish. Texas A&M recommends products containing bifenthrin, lambda-cyhalothrin, cypermethrin, permethrin or deltamethrin as effective against silverfish. Memorial University's Department of Biology recommends preparations containing Propoxur, available at many garden centers and home stores nationwide. Always read pesticide labels and follow the directions carefully.
Jeanne Grunert has been a writer since 1990. Covering business, marketing, gardening and health topics, her work has appeared in the "Chicken Soup for the Soul" books, "Horse Illustrated" and many national publications. Grunert earned her Master of Arts in writing from Queens College and a Master of Science in direct and interactive marketing from New York University.