Silverfish are small, wingless insects commonly found indoors, known for their distinctive silvery-grey color and fish-like movements. These nocturnal creatures are typically about ¾ inch long with a flattened, elongated body and three tail-like appendages at their rear. Silverfish are household pests that can cause damage to various items within a home. They are quick movers, darting away when disturbed, and hide during the day.
Geographic Presence Across the US
Silverfish are found globally and are ubiquitous throughout the United States. While present in all 50 states, their prevalence is higher in humid climates. Different species, such as the common silverfish and the grey silverfish, are found across North America. The grey silverfish is reported across the U.S., particularly in the southernmost states and from the Midwest to California. They consistently seek out moist conditions.
Common Indoor Habitats
Silverfish commonly inhabit dark, undisturbed, and humid areas within homes. These insects are frequently found in bathrooms, kitchens, basements, and attics, which provide damp conditions they prefer. Other typical hiding spots include sinks, bathtubs, laundry rooms, and closets. They can also be found in storage areas like garages, wall voids, and crawl spaces. Inside these spaces, silverfish will hide behind baseboards, under appliances, in cracks and crevices, or within stored items such as old books and cardboard boxes.
Environmental Factors Attracting Them
Silverfish are primarily attracted to environments with high humidity, typically requiring a relative humidity between 75% and 95% to thrive. While they can survive in lower humidity for short periods, consistent moisture is crucial for their survival and reproduction. They also prefer moderate temperatures, often seeking out areas between 70°F and 90°F.
Beyond humidity and temperature, silverfish are drawn to specific food sources rich in carbohydrates and starches. Their diet includes paper products, such as books, magazines, and wallpaper, as well as the glue found in bindings and adhesives. They also consume natural fibers like cotton, linen, silk, and other textiles, especially if they contain starch or sugar residues. Additionally, silverfish feed on pantry items like flour, oats, cereals, dried meat, and pet food. They are opportunistic feeders, consuming organic matter such as dead insects, hair, and even dandruff.