What Are Silverfish and How to Get Rid of Them?

What Are Silverfish?

Silverfish are an ancient insect that has existed on Earth for hundreds of millions of years. Despite the name "fish," they are not fish — they're an ancient type of insect. Here are their basic features and habits:

Physical Features

• Body shape: Slender and flattened, 10-15mm long.
• Color: Silvery-gray or grayish-brown with a metallic sheen.
• Tail: Three long, slender appendages at the rear, resembling a fish's tail.
• Movement: They move with a wriggling, fish-like motion — hence the name "silverfish."
• Wings: Wingless, cannot fly.

Behavior and Habits

• Activity: Nocturnal. They hide in cracks and crevices during the day and come out to feed at night.
• Diet: Feed on substances containing starch and sugar — bookbinding glue, paper fibers, wallpaper paste, starch sizing on clothes, flour crumbs, sugar granules, and more.
• Lifespan: Adults can live 2-8 years, which is remarkably long for an insect.
• Reproduction: A female can lay 50-100 eggs in her lifetime. Eggs hatch in 2-6 weeks (depending on temperature and humidity). The nymph stage lasts 3-24 months. Eggs are laid in cracks; hatching time is heavily influenced by temperature and humidity.

Preferred Habitat

Silverfish like warm, humid environments (75-95% humidity). The most common places to find them at home:

• Bookshelves and bookcases — old book spine glue is a favorite food.
• Wardrobes — starch sizing on clothes and sweat residues attract them.
• Baseboards and floor cracks — damp crevices are their hiding spots.
• Under bathroom and kitchen sinks — high humidity and food crumbs.

Silverfish Look Scary But Are Harmless to People

Silverfish don't bite, don't feed on blood, and don't spread disease. Their main damage is to books, wallpaper, and clothing.