Earwigs and Silverfish in Idaho: Identification and Control Guide
Read Article
Danger Level: 2/5
Silverfish
Lepisma saccharina
Updated May 2026 · Boise, ID
Silverfish are small, carrot-shaped bugs covered in silvery scales. They have two long antennae and three tail-like appendages off the back end. The name comes from how they move (a fish-like, wigglin...
Quick Facts
Size12-19mm long
ColorSilver-gray, metallic
Lifespan2-8 years
Active SeasonsYear-round
Common LocationsBathrooms, Basements, Attics
100%
Satisfaction Guarantee
4.9/5
Customer Rating
24hr
Response Time
Identification
How to Identify Silverfish
Quick Answer
Silverfish are small, carrot-shaped bugs covered in silvery scales. They have two long antennae and three tail-like appendages off the back end.
Silverfish are small, carrot-shaped bugs covered in silvery scales. They have two long antennae and three tail-like appendages off the back end. The name comes from how they move (a fish-like, wiggling shimmy across the bathroom tile at night). They're wingless and stick to dark, humid spots.
Behavior
Silverfish Behavior & Habits
Understanding how silverfish behave helps prevent infestations
Silverfish hide all day and come out after the lights go off. They live an unusually long time for a bug, up to 8 years. Their diet is starch and sugar, which means paper, book bindings, wallpaper paste, cardboard, and even starched clothing. They can survive months between meals as long as the humidity stays up.
Dangers
Silverfish Risks & Dangers
What silverfish can do to your health and property
Health Risks
Silverfish don't bite and don't carry disease. They're mostly a nuisance, though a small number of people are allergic to the scales they shed into household dust.
Property Damage
Silverfish chew through books, papers, wallpaper, photos, and clothing. Anything with starch or cellulose is fair game. The damage shows up slowly, so a stored box of family photos or a forgotten shelf of paperbacks in the basement can take a real hit before anyone notices.
Warning Signs
Signs of Silverfish Infestation
Look for these indicators in your home
Fish-shaped, silver bugs darting along bathroom tile or basement floors at night
Tiny yellow stains or pinhole chew marks on books, photos, and stored paperwork
Pepper-like specks (their feces) in drawers, closets, and inside cardboard boxes
Shed scales that look like fine silver dust in storage areas
Loose wallpaper edges and chewed book bindings, especially in humid rooms
Silverfish in Boise & the Treasure Valley
Most of our silverfish calls come out of older homes with full basements. The North End, East End, Hyde Park, and the Boise Bench see the most of them because of the mix of finished or partially finished basements, original plumbing, and stored boxes that have sat untouched for years. We also see them in newer Meridian and Eagle builds when a master bathroom vent fan is undersized or rarely used. The dry Treasure Valley summer keeps overall silverfish pressure low, but the humid pockets under sinks, behind tubs, and in cool basements stay perfect for them year-round.
Our Solution
How We Eliminate Silverfish
Professional treatment for complete elimination
Silverfish control comes down to two things: cutting the humidity and treating where they hide. We apply residual products along baseboards and behind plumbing fixtures, dust wall voids and attics, and walk the moisture sources with you. Because silverfish live for years and reproduce slowly, the population thins over weeks instead of overnight. New customers start at $49 for the first service.
Prevention
How to Prevent Silverfish
Steps you can take to reduce the risk of infestation
1
Run a dehumidifier in basements and ground-floor bathrooms (silverfish drop off fast below 50% humidity)2
Fix drippy faucets, slow drains, and any leak under cabinets. That is the #1 source on most calls3
Store books, photos, and old paperwork in sealed plastic bins instead of cardboard4
Vacuum baseboards, closet corners, and under furniture to pull out scales and eggs5
Seal cracks around tubs, sinks, and baseboards with caulk6
Run the bathroom fan during and after every shower, and crack a window if the basement smells mustyFAQ
Silverfish Questions Answered
Common questions about identification, prevention, and treatment
Why do I have silverfish?
Silverfish thrive in humid spots with starchy food nearby, which is why bathrooms, basements, and stored boxes of paper or cardboard are the hot zones. In Boise, an undersized bathroom fan, a slow leak under a sink, or an unfinished basement is almost always the trigger.
Are silverfish dangerous to my kids or pets?
No. Silverfish don't bite, sting, or spread disease, so they're safe around children and pets. The real concern is the slow damage they cause to stored books, photos, and clothing, plus a possible allergy to their shed scales in a few sensitive people.
How long does it take to get rid of a silverfish problem?
Plan on 4 to 8 weeks of steady improvement, not an overnight fix. Silverfish live up to 8 years and reproduce slowly, so the population drops as adults die off and the eggs don't get replaced. Fixing the moisture source matters more than any spray. A working bathroom fan and a basement dehumidifier do most of the long-term work.
Related
Similar Pests
Learn about other pests in this category
Read Next
Related Guides
Expert articles related to silverfish in Idaho