How to Get Rid of Silverfish: A Step-by-Step Guide That Actually Works

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You’re reading in bed. Movement catches your eye. A slim, silvery insect

darts across the baseboard and disappears behind the dresser. Fast — faster

than you’d expect. You jump up, move the furniture, and find nothing.

That was a **silverfish**. And where there’s one, there are usually more.

Silverfish don’t bite. They don’t spread disease. But they destroy things —

books, wallpaper, clothing, important documents. They’re also a sign of a

moisture problem that needs to be addressed. This guide will help you eliminate

them and keep them from coming back.

What Are Silverfish?

Silverfish (*Lepisma saccharinum*) are primitive, wingless insects that have

existed for over 400 million years — they were here before the dinosaurs.

Their name comes from their silvery-gray color and fish-like, wriggling

movement.

Close-up of silverfish on a white background

*Caption: Silverfish (Lepisma saccharinum). Note the three tail-like appendages

at the rear and the long antennae — distinctive features visible even from a

distance.*

Why They’re a Problem

Paper products	Books, documents, photos, wallpaper	Moderate
Damage Type	What They Target	Severity
Clothing	Cotton, linen, silk (natural fibers)	Light to moderate
Food	Flour, cereal, pet food (dry goods)	Light
Wallpaper	The paste/glue behind wallpaper	Can cause peeling
Structural	None — they don’t damage wood or buildings	None

They don’t bite humans and aren’t known to transmit disease. The main concern

is property damage, especially to irreplaceable items like old books or

photographs.

Why Are Silverfish in Your Home?

Silverfish need two things: **moisture** and **starch**.

They Thrive In:

**High humidity** (above 75% relative humidity — common in bathrooms,

basements, and laundry rooms)

Temperatures between **70–80°F** (21–27°C)
Dark, undisturbed spaces

What Attracts Them:

Paper	Books, cardboard boxes, magazines, documents	Cellulose + starch in paper
Attractant	Examples	Why
Fabric	Cotton, linen, silk clothing and bedding	Natural fibers contain starch
Adhesives	Wallpaper paste, book bindings, envelope glue	High starch content
Food crumbs	Flour, cereal, pet food, dried pasta	Carbohydrate source
Dead insects	Spider webs, dead bugs in corners	Protein supplement

Where to Look:

Silverfish are nocturnal and hide during the day. Check these locations:

**Bathroom**: Behind toilets, under sink cabinets, in linen closets
**Kitchen**: Behind appliances, in pantry corners, under the sink
**Basement**: Cardboard boxes, stored papers, laundry area
**Bedroom**: Behind bookcases, in closets (especially if humidity is high)
**Attic**: Stored boxes of documents, old books, fabric

Step 1: Reduce Moisture (The Root Cause)

Silverfish cannot survive in dry environments. **Moisture control is the

single most important long-term solution.**

Actions You Can Take Today

Action	Impact	Effort
Run bathroom exhaust fan during and 20 min after showers	High	Zero (just use it)
Fix leaky faucets and pipes	High	Low to moderate
Use a dehumidifier in basement or humid rooms	High	Plug it in, set to 50% RH
Improve ventilation in humid rooms	Medium	Open windows, use fans
Seal gaps around tub/shower edges with silicone caulk	Medium	30 min DIY
Don’t store books or cardboard in humid rooms	Medium	Move them

**Target**: Get indoor humidity below 50–55%. Use an inexpensive

**hygrometer** ($5–10) to monitor problem rooms.

**[AFFILIATE: Hygrometer / humidity monitor — $5-10, essential first tool]**

Step 2: Remove Food Sources

Silverfish can survive for months without food, but removing their food

sources forces them to search elsewhere and makes traps more effective.

Immediate Actions

**Remove cardboard boxes.** Replace with plastic storage bins with tight

lids. Cardboard is both food and shelter for silverfish.

**Seal dry goods.** Transfer flour, cereal, pasta, and pet food into

airtight containers (glass, heavy plastic, or metal).

**Vacuum thoroughly.** Pay special attention to baseboards, behind furniture,

inside closets, and under appliances. Dispose of the vacuum bag outside

immediately.

**Reduce clutter.** Piles of magazines, newspapers, old documents, and

cardboard are silverfish buffets. Recycle or store properly.

**Book maintenance.** If you have valuable books, periodically remove them

from shelves, dust them, and inspect for damage.

Step 3: Kill Existing Silverfish

After reducing moisture and food, it’s time to eliminate the silverfish

already inside your home. Here are the methods, ranked from least to most

chemical.

Method 1: Diatomaceous Earth (Recommended)

**Food-grade diatomaceous earth (DE)** is a fine powder made from fossilized

algae. It’s one of the most effective silverfish killers because:

The microscopic sharp edges cut through the insect’s exoskeleton
The powder absorbs their waxy outer layer, causing dehydration
Silverfish walking through DE die within 24–48 hours
It’s non-toxic to humans and pets (food-grade DE only)
It remains effective as long as it stays dry

**How to apply DE for silverfish:**

Buy **food-grade** diatomaceous earth (not pool-grade — that’s chemically

treated and hazardous)

Wear a dust mask during application (DE dust can irritate lungs)
Apply a **very fine, barely visible** dusting along baseboards, behind

appliances, under sinks, in cabinet corners

Focus on areas where you’ve seen silverfish and along walls
Reapply after cleaning or if the area gets wet
Leave in place for at least 2 weeks

**[AFFILIATE: Food-grade diatomaceous earth product link]**

> **Safety Note**: While food-grade DE is non-toxic, the fine dust can irritate

> lungs if inhaled. Always wear a dust mask during application. Keep pets away

> from treated areas until the dust settles (15–30 minutes).

Method 2: Boric Acid

Boric acid is a white powder that kills silverfish on contact and through

ingestion. It’s more potent than DE but requires more caution.

**[AFFILIATE: Boric acid powder product link]**

Apply in the same locations as DE — baseboards, cracks, behind appliances
More effective than DE but slightly toxic to pets if ingested in quantity
Do not use in areas accessible to children or pets
Consider using only in enclosed spaces (behind appliances, in wall voids)

Method 3: Silverfish Traps

Sticky traps are useful for monitoring and reducing smaller populations:

Place traps along walls, in corners, under sinks
They won’t eliminate an infestation alone, but help track severity
Replace when full or every 4–6 weeks
Used traps tell you where activity is concentrated

**[AFFILIATE: Sticky trap / insect glue trap product link]**

Method 4: Insecticide Sprays (Use Selectively)

Pyrethrin-based sprays labeled for silverfish can provide quick knockdown of

visible insects. They’re best used as a supplement to DE or boric acid, not

as the primary solution.

> **Safety Warning**: Always read and follow the product label instructions.

> Never spray insecticides near food preparation surfaces, pet areas, or

> children’s rooms. Insecticides are pesticides regulated by the EPA — the

> label is the law.

Step 4: Seal Entry Points

Silverfish can squeeze through gaps as thin as a credit card.

Sealing Checklist

[ ] Caulk gaps around baseboards and floorboards
[ ] Seal cracks in walls, especially where pipes enter
[ ] Install door sweeps on doors leading to basement or garage
[ ] Seal gaps around window frames with weatherstripping
[ ] Fill holes in walls from old picture hooks or fixtures
[ ] Use expanding foam to seal larger gaps around utility penetrations

Sealing also helps with moisture control by reducing humid air infiltration.

Natural Remedies: What Works and What Doesn’t

Cedar shavings/oil	Moderate	Repels but doesn’t kill; needs frequent refreshing
Remedy	Effectiveness	Notes
Cinnamon	Low	Silverfish reportedly dislike it, but not a reliable solution
Lavender sachets	Low	Pleasant smell, minimal pest control effect
Cucumber peels	Very low	A popular internet remedy; no scientific evidence it works
Salt	Low	Unlike DE, salt doesn’t have the same desiccating structure
Citrus sprays	Low	Mild repellent at best; dissipates quickly
Bay leaves	Low–Mod	Traditional repellent; place in drawers and bookshelves

**Bottom line**: Natural repellents may help slightly but will not eliminate

an established infestation. Use them as a supplement to moisture control and

DE, not as your primary strategy.

The 3-Week Silverfish Elimination Protocol

Week 1	Environment	Fix leaks, start dehumidifier, remove cardboard, vacuum thoroughly, seal dry goods
Week	Focus	Actions
Week 2	Kill	Apply DE along baseboards and hot spots, place sticky traps, seal entry points
Week 3	Monitor	Check traps, reapply DE in high-traffic areas, continue dehumidifying

After 3 weeks, you should see a significant reduction in silverfish sightings.

If they persist, the humidity is probably still too high or there’s a hidden

breeding site you haven’t found.

When to Call a Professional

Call a pest control professional if:

Silverfish persist after 4+ weeks of consistent treatment
You find extensive damage to books, documents, or clothing
You have a recurring problem in multiple rooms
You cannot locate the moisture source
You live in a multi-unit building where the source may be in another unit

Professionals have access to commercial-grade desiccants and can apply

treatments in wall voids and other inaccessible areas.

Frequently Asked Questions

Do silverfish bite people?

No. Silverfish do not bite, sting, or transmit disease. They are harmless to

human health — the only concern is property damage.

Can silverfish climb walls?

Yes. Silverfish can climb smooth vertical surfaces and are often seen on walls

and ceilings in bathrooms. Their ability to climb is one reason why treating

baseboards alone isn’t always sufficient.

How many silverfish is an infestation?

Seeing one silverfish occasionally is normal. Seeing 2–3 per week probably

indicates a moisture problem worth addressing. Seeing multiple silverfish

nightly means you have an established infestation.

Do silverfish mean my house is dirty?

No. Silverfish are attracted to moisture and starch, not general dirt or food

waste. They’re equally common in clean and messy homes.

Will a dehumidifier really solve the problem?

A dehumidifier alone isn’t usually enough to eliminate an existing infestation,

but it’s one of the most effective long-term prevention tools. Silverfish

cannot reproduce in consistently low humidity (below 50% RH).

Related Guides

[Silverfish Identification Guide: What They Look Like & Where They Hide](/silverfish-identification/)
[The Complete Guide to Diatomaceous Earth for Pest Control](/diatomaceous-earth-for-pests/)
[Natural Silverfish Remedies That Actually Work](/natural-silverfish-remedy/)
[Home Pest Prevention Checklist](/home-pest-prevention-checklist/)

**Safety Notice**: Pest control products, including diatomaceous earth and

boric acid, must be used according to label directions. Always read and follow

product labels. Keep pest control products out of reach of children and pets.