Are Silverfish Harmful?

Do Silverfish Bite?

Silverfish do not bite. This is many people's first concern when they see a silverfish, but there's nothing to worry about. Silverfish are widely distributed around the world and are common pests in libraries and museums, where they can threaten antique books and artifacts.

Why Don't Silverfish Bite?

Silverfish have chewing mouthparts suited for gnawing on paper, fabric fibers, and food crumbs — like a tiny pair of scissors. This mouthpart structure simply doesn't have the strength to pierce or cut through human skin. They don't feed on blood either and have zero interest in human blood or tissue.

Silverfish Have No Direct Aggression Toward Humans

• Don't bite, don't sting, don't feed on blood.
• Don't parasitize people or pets.
• Don't spread disease.
• Pose no direct health threat to humans. They won't actively crawl toward your bed or body — they avoid light and people.
• Photophobic: they hide in crevices during the day and only come out at night.

Actual Damage Caused by Silverfish

Although harmless to people, silverfish do damage household items:

1. Books — Gnaw on book spine glue and paper edges, leaving irregular gnaw marks.
2. Clothing — Especially attracted to starched shirt collars and cuffs, chewing small holes.
3. Wallpaper — Feed on the glue behind wallpaper, causing it to peel.
4. Important documents — Photos, albums, and file archives can have their edges gnawed.
5. Stains they leave behind — Silverfish leave pale yellowish stains and tiny black specks (droppings) wherever they crawl, marring surfaces. Their ability to survive without food is remarkable — they can live over 300 days without eating, meaning they can persist even in vacant rooms.

How to Tell If Damage Is from Silverfish?

If you find small holes in clothes or books but aren't sure what caused them:

• Silverfish gnaw marks: Irregular edges, small patchy feeding patterns.
• Clothes moth larva gnaw marks: More regular edges, roundish holes.
• Cockroach gnaw marks: Large gnawed areas with rough edges.

Don't be afraid when you see a silverfish. They pose no health threat, but it's best to deal with them promptly to protect your belongings.