Size: About ¼ to ½ inches long, with a “carrot-shaped” body that’s thicker near the head and thinner toward the posterior.
Color: Dark grey or silver, with metallic-looking or shining scales
Body: Silverfish are also sometimes called “bristletails”, because of three tail-like appendages on the rear of their abdomens. The two “bristles” that point sideways are called “cerci”, while the one that points straight backward is called a “filament.”
Silverfish are often found around packing materials that have remained stationary for a long time. They retreat from light very quickly when they’re encountered. Silverfish are also common around any areas where they can access moisture. You may find silverfish bodies or remains near plumbing fixtures.
Silverfish may leave behind bite marks, waste, or shed skin behind. Though they can’t inflict significant damage, they may chew through paper products, linen, adhesive, or other materials in their pursuit of sugary food materials.
Scientific Order: Zygentoma
Silverfish name: Lepisma saccharina
Silverfish are drawn toward humid areas. The best ways to prevent Silverfish include:
Reduce indoor moisture and humidity and make your building less attractive to silverfish. Patch cracks around the doors, windows, ceiling, and foundation to deprive silverfish of hiding places, and possible access points.
Silverfish dislike direct light and need to live in enclosed, dark areas. Deprive silverfish of potential hiding places by storing packages, boxes, other storage material off the ground. Let natural light into rooms whenever possible and keep naturally dark rooms like basements or attics clean. Store paper products in elevated, inaccessible locations whenever possible.
Silverfish feed on carbohydrates like sugars and starches. They infest vegetables, flour, cereal, dried foods, dead insects, beef, and sweet foods. If they can’t access carb-rich food, silverfish can also subsist on the starches found in fabrics, paper, glue and other adhesives, bookbinding, photographs, and more.
They prefer dark, moist, and warm locations. They’re commonly found near bathtubs, sinks, closets, basements and other humid locations. The ideal temperature for silverfish is between 70- and 80-degrees Fahrenheit, with a relative humidity between 75 and 95 percent.
The duration of a silverfish life cycle is primarily determined by the temperature of the rearing environment. A female silverfish will produce several fertilized eggs after mating and can produce around 100 eggs in her lifetime. She lays her eggs in crevices, on cloth and in food or dust. In warm environments, these eggs may hatch in as few as 19 days. In colder environments, eggs can remain dormant for up to six weeks and will hatch when temperatures rise.
Silverfish grow slowly and must shed their skin or “molt” several times. Immature silverfish look like their adult counterparts, except they’re smaller and don’t yet possess scales. Silverfish can live three years or longer in humid and predator-free environments.
University of Minnesota Extension’s Silverfish and firebrats in homes page
Cornell University Dept. of Entomology Insect Diagnostic Laboratory “Silverfish and Firebrats” fact sheet
Penn State College of Agricultural Sciences Department of Entomology’s Bristletails (Silverfish and Firebrats) page
No. They have very weak mandibles that are not capable of biting. They scrape the surface of paper products or food to acquire nutrition. They’re also terminally shy and will probably skitter away before you have any chance to worry about a silverfish bite.
While they are known to eat cardboard, paper, books, wallpaper and other textiles, they prefer dried starchy foods like grains and cereals or pet food. They can survive months without eating.
Silverfish are not particularly harmful, although their appearance can be startling. They don’t bite or carry disease, but they can damage books, boxes, clothing and upholstery. They may leave behind a yellow waste smear.
There are 24 species of bristletails in the U.S. but only a few that you’re likely to find in your home. These include the common silverfish, the gray silverfish, the four lined silverfish and the firebrat which prefers warmer temperatures.
The name comes from the small, silvery scales on their bodies. These scales detach very easily, which makes silverfish surprisingly difficult for predators to grab onto.
Silverfish typically live 2-3 years in favorable conditions, but the common silverfish can live up to eight years.
Silverfish have two long, slender antennae or “feelers." Silverfish use highly developed sense receptors in these antennae as their primary means of navigating environments.
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