How to Get Rid of Silverfish
To get rid of silverfish, dry out their habitat: run a dehumidifier and exhaust fans to pull indoor humidity down, fix leaks, seal cracks, and store food and paper in airtight containers. Pair that with sticky or jar traps to catch the ones already inside.
By James Okonkwo
·Senior Reporter ·
·
5 min read
To get rid of silverfish, dry out the places they love and cut off their food. Silverfish are moisture pests, so the lasting fix is lowering indoor humidity with a dehumidifier and exhaust fans, fixing leaks, sealing cracks, and storing starchy food and paper in airtight containers. Traps clean up the ones already inside while the environment turns against them.
What are silverfish and why are they in my home?
Silverfish are small, wingless, teardrop-shaped insects, usually silvery-gray, with two long antennae and three bristle-like tails. They move in a quick, wriggling motion that looks a bit like a swimming fish. They are nocturnal and prefer dark, humid places.
They show up because a home offers two things they need: moisture and starch. Damp bathrooms, basements, crawl spaces, and attics supply the humidity, while paper, cardboard, book bindings, wallpaper glue, cereal, and dry pet food supply the food. Reduce either and the population shrinks.
Why does humidity matter so much?
Silverfish depend on humid air to survive and reproduce, and they struggle in dry conditions. Keeping indoor humidity in a comfortable, lower range (many guides suggest roughly 30 to 50 percent) acts like population control. Practical ways to drop humidity:
- Run a dehumidifier in damp basements, laundry rooms, and crawl spaces.
- Use bathroom and kitchen exhaust fans during and after showering or cooking, and leave them on for a while afterward.
- Improve air circulation and ventilation in closed, stuffy rooms.
- Fix dripping pipes, leaky fixtures, and condensation around toilets, sinks, and water heaters.
This single step does more over time than any spray.
How do I trap the silverfish already inside?
Traps both reduce numbers and show you where silverfish are concentrated. Effective, low-toxicity options include:
- Sticky traps: Place store-bought or DIY sticky traps (double-sided tape on cardboard, baited with a crumb of bread) along baseboards and in corners.
- Glass jar trap: Wrap the outside of a small glass jar with tape so insects can climb up, add a bit of starchy bait, and set it upright. Silverfish climb in but can’t climb back up the smooth inner glass.
- Rolled wet-paper trap: Dampen a rolled newspaper secured with rubber bands and leave it out overnight; silverfish gather inside, and you discard the whole roll.
Check and replace traps every few days until catches drop off.
Should I use bait or insecticide?
For heavier infestations, targeted products can help, but use them carefully:
| Option | How it works | Notes |
|---|---|---|
| Dehumidifier + fans | Makes habitat unlivable | Most important long-term step |
| Sticky / jar traps | Catch and monitor adults | Low toxicity, safe around most homes |
| Diatomaceous earth | Dries out insects that crawl through it | Use food-grade; apply thin lines in dry cracks per label |
| Boric-acid / labeled baits | Kills over time as they feed | Keep away from kids and pets; follow the product label |
| Contact spray | Kills on contact | Quick knockdown only; won’t fix the cause |
Whenever you use any pesticide or dust, follow the product label for where and how much to apply.
How do I stop silverfish from coming back?
Prevention combines dryness, food control, and sealing:
- Store cereal, flour, pet food, and other dry goods in airtight containers.
- Move books, magazines, and important papers out of damp basements and attics; use sealed plastic bins instead of cardboard.
- Declutter stacks of paper and cardboard that give them food and shelter.
- Seal cracks and gaps around baseboards, pipes, windows, and the foundation with caulk.
- Vacuum regularly, paying attention to corners, closets, and under furniture, to remove eggs and food crumbs.
What damage do silverfish cause, and how long until they’re gone?
Silverfish are destructive to belongings rather than to the house itself. They feed on starchy, carbohydrate-rich materials, which means book bindings and pages, wallpaper and its paste, cardboard, photographs, dry foods, and sometimes natural fabrics and clothing can all show nibbled edges, yellow stains, or small irregular holes. A few silverfish rarely do noticeable harm, but a long-running infestation in a damp basement or attic can quietly ruin stored papers and keepsakes.
As for timing, silverfish are slow-breeding compared with many household pests, so patience matters. Expect trap catches to climb at first (because you are finally seeing what was hidden), then taper over several weeks as the environment dries out and food sources disappear. The parts of the plan that end an infestation for good are the slow ones: sustained low humidity and sealed storage. If you only knock down the adults you see, the population quietly rebuilds, so keep the dehumidifier running and the traps out for at least a month after you stop spotting them.
When should I call a professional?
Most silverfish problems respond to humidity control and sealing. Call a licensed pest-control professional if you still see large numbers after several weeks of drying out the home, if silverfish appear throughout multiple rooms, or if you suspect a chronic moisture problem (such as a hidden leak or poor crawl-space ventilation) you can’t resolve yourself. A pro can identify moisture sources and apply treatments safely. This is practical guidance, not medical advice; if anyone in the home has allergy or asthma concerns about dust or insects, consult a healthcare provider.
Frequently asked questions
What causes silverfish in the home?
Silverfish are drawn to damp, humid areas and starchy foods like paper, glue, cardboard, and cereals. High humidity in bathrooms, basements, and crawl spaces, plus accessible food, is the usual cause.
What do silverfish hate?
Silverfish avoid dry conditions and strong-smelling substances. Lowering humidity is the biggest deterrent; many people also report that scents like cedar sometimes help, though results vary.
Are silverfish harmful to humans?
Silverfish do not bite people or spread disease. Their main harm is damage to books, wallpaper, clothing, and stored food, and in large numbers they can trigger allergies in some people.
Do silverfish mean my house is dirty?
Not necessarily. Silverfish are drawn to moisture more than mess, so even a clean home with high humidity or a damp basement can attract them.
What kills silverfish instantly?
Contact sprays labeled for household insects can kill silverfish on sight, but used alone they do not solve an infestation. Reducing humidity and sealing food and cracks is what prevents them from returning.
Where do silverfish hide during the day?
Silverfish are nocturnal and hide in dark, humid gaps: under sinks, behind baseboards, in cardboard boxes, inside wall voids, and among stored books and papers.
