Common Silverfish

Lepisma saccharinum · Order: Zygentoma · Family: Lepismatidae

Also called: Silverfish, Silver Fish

Can damage your home. Silverfish can damage household items such as wallpaper and tapestries.

Common Silverfish — Photo: Christian Fischer, CC BY-SA

Silverfish are small, nocturnal insects about 7 to 10 mm long with a tapered, fish-like abdomen that becomes a metallic grey as they age. They thrive in moist indoor spots like basements, bathrooms, kitchens and attics, needing humidity between 75 % and 95 %. These insects feed on starchy substances, paper adhesives, cotton, silk and even their own shed skins, which can lead to damage of walls, fabrics and stored food.

Source: Wikipedia

How to recognize it

The abdomen narrows to a point, giving the bug a shape that resembles a tiny fish. Young ones start out white and turn a greyish, metallic shade as they mature.

Source: Wikipedia

Size

Adults are typically 7 to 10 mm (about 0.3 to 0.4 in) long and are active at night.

Source: Wikipedia

Is it a pest in the house?

Because they eat adhesives and fabrics, they can damage wallpaper, tapestries and other household items.

Source: Wikipedia

Does it bite or sting?

Silverfish do not spread disease to people.

Source: Wikipedia

How to get rid of it

Essential oil from Japanese cedar has shown promise as a repellent and insecticide against silverfish. Natural predators such as house centipedes and spiders like the spitting spider can also help keep silverfish numbers down.

Source: Wikipedia

Where it lives

They need high humidity, usually between 75 % and 95 %, and are found in damp places such as basements, attics, bathrooms, kitchens and even libraries.

Source: Wikipedia

What it eats

They eat anything containing starches or dextrin, like glue, paper paste, and leftover crumbs. Other foods include cotton, linen, silk, dead insects and even their own molted skins.

Source: Wikipedia

Life cycle

Nymphs hatch looking like tiny, white adults and later develop the typical grey metallic color. A single silverfish may molt anywhere from 17 up to 66 times during its life, sometimes over 30 times in one year.

Source: Wikipedia

Lookalikes

Other silverfish species in North America include Ctenolepisma longicaudatum and Ctenolepisma quadriseriatum, while the firebrat looks similar but has a mottled gray-brown body.

Source: Wikipedia

Where it is found in the US

Recorded in 47 of 51 states and DC. Most records: Pennsylvania, Minnesota, New York, Indiana, Colorado, Ohio, Washington, Illinois.

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Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Status: introduced in Canada. Source: iNaturalist

Months it is reported in the US

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Source: GBIF

More photos

Common Silverfish photo 3 — Photo: anonymous, CC BY-SA

Common Silverfish photo 4 — Photo: czernybug, CC BY

Common Silverfish photo 5 — Photo: unknown, CC0

Common Silverfish photo 6 — Photo: jerr17, CC BY

Questions people ask

What do silverfish look like?

They have a tapered, fish-shaped abdomen and turn from white when young to a metallic grey as they age.

Source: Wikipedia

Where in my home might I find silverfish?

They prefer moist areas such as basements, attics, bathrooms, kitchens, sinks and even libraries, needing high humidity.

Source: Wikipedia

How can I get rid of silverfish?

Japanese cedar essential oil has been found effective as a repellent, and natural predators like house centipedes and spitting spiders also help control them.

Source: Wikipedia