Pest description and damage Slender insects about 0.375 inch long, wingless, grayish silver or mottled gray, with two long antennae and three long filaments at the tail. They prefer starchy food including paper, paste, and starched clothing. These insects are commonly seen in homes that have wood shake roofs, and they prefer a warmer climate, such as found in attics. Very tolerant of high temperatures.
These insects can be associated with damp conditions in basements, bathrooms, or warehouses. Reducing humidity often eliminates the problem. Do not store cardboard boxes directly on concrete floors. Household insecticides are effective if the infestation is not manageable by other means. Replacing wood shake roofs with non-wood roofing material may be advisable. In some cases silverfish problems should be handled by a professional pest control company. Insulation treated with borates can be applied over the existing insulation in attic spaces to provide additional control of silverfish. A non-chemical way of trapping silverfish is to apply masking tape to the exterior of a glass jar, this will allow the silverfish to climb up into the jar. Place two to three tablespoons of dry oatmeal in the jar. Silverfish entering the jar cannot climb up the smooth interior. The oatmeal must be replaced every few weeks to avoid other stored product pests from infesting the oatmeal, which can lead to an infestation elsewhere in the home.
For further information:
Silverfish and Firebrats. WSU Extension Community Horticulture Fact Sheet #87. https://s3.wp.wsu.edu/uploads/sites/2053/2015/09/87SilverfishFirebrats.pdf