How to Get Rid of Silverfish (2026 Guide)

Silverfish are a humidity gauge with legs. Where they parade nightly across bathroom floors and basement shelves, moisture sits above 60 percent and starch waits nearby in bindings, boxes and wallpaper paste. Kill the visible ones and the gauge refills within weeks, because the conditions manufacture replacements. Dry the rooms below 50 percent humidity first, and the same insects that shrugged off sprays start dying of exposure while dusts finally work. Every tactic below obeys that order: moisture, food, shelter, and only then chemistry.

What are these teardrop insects?

Common silverfish is the wingless, carrot-shaped insect, about half an inch long, silver-gray, with two long antennae and three tail filaments trailing behind. It cannot fly or bite. It grazes starches and cellulose: book bindings, wallpaper adhesive, cardboard sizing, cereals, flour, pet food, dead skin and hair. Finding one occasionally means little. Finding them nightly means a damp harborage with food is supporting a breeding population, and the hotspots run predictably through bathrooms, basements, laundry rooms, attics and book-heavy closets.

A newer cousin complicates the picture. Long-tailed silverfish spread through dry rooms and offices where classic control centered on dampness underperforms, a pattern Penn State researchers flagged after tracing infestations across arid interiors. If traps fill in rooms your hygrometer calls dry, suspect the long-tailed species and weight the food-sealing and crack-dusting steps heavier than further dehumidifying.

Long-tailed and gray cousins tolerate drier rooms than classic silverfish, so dry-room catches need food-first tactics.

How do I dry the house below 50 percent?

Measure before buying anything. A ten-dollar hygrometer left two days in each suspect zone beats guessing, and rooms that already sit under 50 percent need food work, not machines. Where readings run high, run a dehumidifier sized for the space with its humidistat set at 45 percent. Empty or drain it on schedule, since a full tank that shuts off at midnight protects nothing.

Fix the water at its source in parallel. Repair dripping traps, sweating cold-water lines and gutter splashback. Vent bathrooms to the outside, not the attic, and run the fan twenty minutes past showers. Crack the laundry room door while machines run, and insulate cold pipes where condensation beads, such as basement runs in summer. These unglamorous repairs outperform every powder, because as one operator puts it, cutting moisture cuts the main attraction itself, and sprays applied over dampness just schedule the sequel.

The 50-percent gate: dry first, dust second

Run this sequence strictly in order and never skip ahead. First, hold every target room below 50 percent humidity for a full week, verified by hygrometer logs, not by feel. Only then puff diatomaceous earth into cracks, since DE clumps useless in dampness and every premature application wastes product and credibility. Finally, set sticky traps as the gate check. Catches in drying rooms should fall across three weeks. Catches in rooms that never dried indict the moisture work, not the dust. Order is the method here, and impatience is the failure mode.

What do I seal, bin and toss?

Starve starch methodically. Move cereals, flour, pet food and snacks into airtight hard containers, including the half-open bags silverfish commute through. Box books, documents and fabrics in sealed plastic bins off damp floors, and replace soggy cardboard moving boxes, which function as both food and nursery. For already-chewed volumes, isolate them in sealed bags before they seed shelves. A few days in a deep freezer kills hitchhikers in small lots. Quarantine stays until neighboring traps run clean for a month. Declutter paper stacks, magazines and storage corners where undisturbed darkness shelters breeding.

Then close the architecture. Caulk baseboard gaps, window trim, pipe penetrations and wall cracks where silverfish travel and lay eggs. Sweep and vacuum shelves, closets and crevices to remove eggs, shed skins and the skin-and-crumb debris that feeds nymphs, and trash vacuum contents outdoors. Outside, rake wet leaves off foundations and grade soil away from walls so exterior dampness stops wicking inward.

Tactic	What it does	Where it fails
Dehumidifier below 50 percent	Removes the core attraction	Undersized units, full tanks, unsealed damp
DE in dry cracks	Dehydrates crossers over weeks	Any dampness, heavy piles that repel
Boric acid dusts	Stomach poison in voids	Needs label-exact dry placement
Sticky traps	Verifies trends room by room	Control alone, never clearance
Airtight bins	Starves paper and pantry feeders	Open bags defeat the system
Sprays alone	Kills visible roamers	Reinfests from damp harborages

How do dusts and traps fit in?

Diatomaceous earth works by physics, not chemistry: microscopic edges score the waxy cuticle until the insect desiccates, usually within one to two weeks of contact. Apply it as a barely visible film with a bulb duster along dry baseboards, behind appliances, under bath fixtures and around utility entries. Heavy drifts repel insects around the treatment, and damp spots neutralize it entirely. In dry wall voids it persists for months, which makes post-drying application the highest-value ten minutes of the campaign.

Boric acid formulations and granular baits cover adjacent niches per their labels, placed only in dry inaccessible cracks away from children, pets and food surfaces. Sticky traps do the bookkeeping: set them in former hotspots, date them, and read trends rather than totals. A declining curve across a month means victory in progress. Flat lines after true sub-50-percent drying mean long-tailed species or a hidden void. That distinction, checkable against the gray-cousin photo above, tells you whether to double down on food sealing or open walls with help.

DE, boric acid or pro? Pick in 30 seconds

• Visible bugs plus damp rooms: dehumidifier and leak repair first. No dust yet.
• Dry rooms with steady catches: thin DE films in cracks, traps to verify.
• Voids and pipe chases you cannot reach: boric dust per label, or a pro with void tools.
• Books and archives at risk: bins plus DE perimeter now, pro assessment this month.
• Several rooms still filling traps after a dry month: stop spending and call help.

Persistent multi-room catches, valuable archive or library damage, and moisture inside chases and voids all end DIY. Pros bring commercial dehumidification, void dusting tools and moisture meters that find the wet framing amateurs miss. Interview them on numbers: ask what humidity target they guarantee, how they verify it room by room, and what monitoring continues after they leave. Silverfish share the vacuum-and-seal religion with carpet beetles, the moisture war with cockroaches and flies, and the pantry discipline of ant and moth defense. Start from the silverfish hub, cross-check every pest, and open the pro finder when gauges stay wet despite honest drying.

How to: How to Get Rid of Silverfish (2026 Guide)

Dry the house, starve the starch-eaters, dust the cracks.

You'll need

• dehumidifier with humidistat
• food-grade diatomaceous earth
• bulb duster
• sticky traps
• airtight bins
• caulk

Tools

• flashlight
• hygrometer

1. Measure and dry every zone

   Place a hygrometer in basement, bathroom and attic for two days. Run dehumidifiers and fix leaks until readings hold below 50 percent.

2. Starve the starch supply

   Bin cereals, pet food and papers airtight. Replace damp cardboard boxes with plastic. Declutter book piles off floors and walls.

3. Dust dry cracks only

   Puff thin DE films into dry baseboard gaps, behind appliances and around pipe entries. Skip any damp spot until it dries.

4. Trap and verify for a month

   Set sticky traps in former hotspots. Declining catches over three to four weeks confirm the program. Flat catches mark the missed moisture.

Frequently asked questions

What attracts silverfish to a house?

Humidity above 60 percent plus starch: book bindings, wallpaper paste, cardboard, cereals and glue. Bathrooms, basements and attics with poor ventilation host most indoor populations.

Does diatomaceous earth kill silverfish?

Yes, but only bone dry. DE shreds their waxy coating and dehydrates them within weeks in dry cracks. In damp rooms it clumps and fails, which is why dehumidifying comes first.

Are silverfish dangerous?

No bites, no disease. Damage runs to stained books, nibbled wallpaper, yellowed papers and contaminated dry goods. The moisture problem behind them usually matters more than the insects.

How long does silverfish removal take?

Weeks. They survive months without feeding, so traps keep catching stragglers after conditions turn hostile. Judge by declining trap trends across three to four weeks, not single sightings.

When should I call a professional for silverfish?

Call when traps fill across several rooms despite sub-50-percent humidity, when damage hits valuable books or archives, or when moisture hides inside wall voids and plumbing chases beyond DIY reach.

Useful links (3)

1. The Spruce: Getting Rid of Silverfish, Expert-Backed (2026)— thespruce.com
2. HowStuffWorks: Silverfish Control Steps (2026)— home.howstuffworks.com
3. TERRO: Silverfish Control (Dust and Moisture Guidance)— terro.com

Photo credits

Thank you to Aiwok and This image is created by user B. Schoenmakers at Waarneming. for sharing these beautiful photographs and helping bring this guide to life.

Wikimedia Commons · CC BY-SA 3.0 · CC BY 3.0