Silverfish (Lepisma saccharina) are fast-moving, silvery-grey insects with three tail filaments and a distinctive teardrop body shape. They favor damp, dark spaces — bathrooms, basements, attics, and kitchen cabinets — and can quietly damage books, wallpaper, cardboard, and clothing while going unnoticed for years.
Why You Have Silverfish
Silverfish thrive when three conditions combine:
- High humidity (above 70 percent)
- Starch-rich food sources (paper, glue, cereal, fabric fibers)
- Dark, undisturbed hiding places
Fast Methods That Actually Work
1. Reduce the Humidity
This is the single most effective silverfish control step. Run a dehumidifier in basements and bathrooms, fix any slow leaks, and ensure bathroom exhaust fans vent outside. Silverfish cannot survive in dry environments.
2. Sprinkle Diatomaceous Earth
Food-grade diatomaceous earth is a natural powder that shreds the waxy cuticle of silverfish, causing them to dehydrate. Dust a thin layer behind appliances, along baseboards, and inside cabinet corners. Safe around children and pets when used as directed.
3. Set Out Sticky Traps
Insect glue boards placed along walls and in closets will catch foraging silverfish and also help you monitor population size.
4. Use Boric Acid Carefully
A light dusting of boric acid in wall voids and under appliances kills silverfish that crawl through it. Keep boric acid out of reach of children and pets — never apply to food preparation surfaces.
5. Declutter Paper and Cardboard
Silverfish love stacks of newspaper, old magazines, and cardboard boxes. Move storage into sealed plastic bins and declutter attics, closets, and basements.
Preventing a Return
- Seal cracks around pipes, baseboards and window frames
- Store dry goods in airtight containers
- Vacuum cracks and crevices regularly
- Keep firewood and cardboard away from the house exterior
When to Call a Professional
Small silverfish populations respond well to DIY control, but large infestations — especially those tied to persistent moisture problems — often need a professional pest control assessment and sometimes structural repairs.