Silverfish are insects often seen in cool, damp, dark areas. They seek and need moisture to live and therefore often appear in bathrooms. Silverfish have slender, pearl-grey or silver-coloured bodies without wings. The insect has scales, and the mature adult is about one-third to a half inch long. Young silverfish resemble the adult. Silverfish move actively at night and avoid sunlight. They scurry out of sight if an object they are hiding under is moved in the daylight. Getting rid of this pest is not difficult if you clean consistently and use the correct products.
Eliminate moisture sources in the bathroom. Hang up damp towels or clothing to air-dry before placing them in a hamper. Repair leaky pipes or dripping faucets. Dry shower stalls, bathtubs and sinks with a towel after using water.
Seal cracks and crevices with caulking in bathroom walls or tiled areas. Silverfish breed and hide in these spots.
Clean the bathroom area well to eliminate any food sources for the silverfish. Organic debris, food particles, book bindings and starched linens are all potential food sources. Other sources are glue or sizing in paper and wallpaper, dust and dead insects.
Spray pyrethrin aerosols and use liquid pesticides containing chlorpyrifos, propoxur or bendiocarb. Apply them in bathroom areas where you spot silverfish. Insecticides are not necessary for light infestations. Proper cleaning and moisture control are effective in controlling occasional sightings of silverfish.
Using a dehumidifier or exhaust fan in the bathroom area decreases the relative humidity so it is not tolerable for silverfish.