Silverfish

What it looks like

• Tear-drop body shape (wider at head, tapering to tail)
• Silvery-gray, metallic sheen
• Three long tail filaments and two antennae
• Wingless, fast, scuttling movement

Where you'll find it

• Bathrooms (under tubs, behind toilets)
• Basements, crawl spaces, and laundry rooms
• Closets and storage areas with cardboard boxes
• Bookshelves and paper storage

Behavior & biology

Silverfish eat starches and sugars — book bindings, wallpaper paste, paper, dry pet food, cereals, photos, and stored fabrics. They prefer humidity above 75% and die in dry conditions. They're long-lived (3-8 years) and slow to reproduce, so populations grow gradually. They're nocturnal and shy — daytime sightings often mean a heavy infestation.

Iowa activity calendar

Signs of an infestation

• Silverfish darting from under the bathmat or in the bathtub at night
• Yellow stains on stored paper and books
• Small irregular holes in book pages, wallpaper, and stored fabrics
• Tiny pepper-like droppings

Health & property risk

No health risk. Damage to books, photos, stored documents, and natural-fiber clothing can be significant in long-running infestations.

How we treat it

1. 1

   Moisture reduction

   Bathroom and basement dehumidification is step one — silverfish die in dry conditions.

2. 2

   Crack & crevice + dust treatment

   Insecticidal dust in wall voids, behind baseboards, and around plumbing penetrations gives long-term residual.

3. 3

   Storage upgrade

   Move stored books and papers off basement floors and into sealed plastic bins. Removes both food source and humidity exposure.

Why DIY usually fails

A basement dehumidifier and storing valuables in plastic bins solves most silverfish problems without treatment.

FAQ