Silverfish are always wingless and are silvery to brown in color because their bodies are covered with fine scales. They are generally soft bodied. Adults are up to 3/4 inch long,flattened from top to bottom, elongated and oval in shape, have 3 long tail projections and 2 long antennae.
Females lay eggs continuously after reaching the adult stage and may lay over 100 eggs during her life. Eggs are deposited singly or in small groups in cracks and crevices and hatch in 3 weeks. Silverfish develop from egg to young to adult within 4 to 6 weeks and continue to molt throughout their life. Immature stages appear similar to adults except they are about 1/20th of an inch long when they first hatch and whitish in color, taking on the adults’ silver coloring as they grow. They are long-lived, surviving from 2 to 8 years.
Silverfish are chewing insects and general feeders but prefer carbohydrates and protein, including flour, dried meat, rolled oats, paper and even glue. They can survive long periods, sometimes over a year, without food but are sensitive to moisture and require a high humidity (75% to 90%) to survive. They also have a temperature preference between 70 and 80 degrees F. They are fast running and mostly active at night and generally prefer lower levels in homes, but may be found in attics.
Silverfish can eat and stain books, fabric, wood and wallpaper but are often considered to be more of a nuisance than a pest.