Silverfish are very common in San Diego County. Silverfish are primitive insects that shed their skin as much as 50 times before reaching the adult stage. They live for several years and feed on a wide variety of materials, including human foods, paper products, fabrics, or glue in books and wallpaper. They are common in woodpiles, fences, attics, and closets. These insects are able to squeeze into tiny cracks to hide or to gain entry. Silverfish range from silvery gray to dark gray with darker lines running front to back on top. Evidence of their presence commonly will be the black, pepper-like fecal droppings that they leave everywhere they roam. Attics often have a huge abundance of the feces lying on insulation or rafters. Evidence of their damage will be holes made by their rasping mouth parts. Silverfish commonly invade a structure from the outside. For interior infestations treatment of attics and wall voids with a green alternative insecticide will be effective, and an exterior treatment around the foundation also helps to prevent their entry.