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What are Silverfish?

Silverfish are primitive nuisance pests that can destroy your books, clothing, and more. Here’s how to identify and prevent these pests from infesting your home.

If you’ve spotted holes in your favorite books, yellow stains on your clothing, or small pellets on your newspaper, you may have a silverfish problem. These primitive pests, named for their shimmery silver bodies and fish-like movements, are more than just creepy. They feast on paper, clothing, upholstery, and more. Nocturnal, nimble, and quick-moving, silverfish can be difficult to eradicate on your own.

That’s where professional pest control companies come in. The best pest control companies can eliminate silverfish infestations and help you prevent the pests from returning.

Identifying Silverfish

Silverfish are ancient insects. According to research and the book “Nature Underfoot,” silverfish have been around for 400 million years—predating dinosaurs. Read on to find out more basics on silverfish characteristics and behavior.


These pests are shiny silver or gray and have slender, flattened, tear-shaped bodies, bristle-like tails, and thread-like antennae. They grow to be between ½-1 inch long. Silverfish continue to molt as adults, shedding their skins and leaving scales behind. These pests have no wings but are extremely fast climbers and crawlers.


Silverfish are not known to be harmful to humans. They do not bite, and there is no scientific evidence that they are poisonous or carry disease. However, their molted skins can trigger allergic reactions.


Silverfish are drawn to moisture, and often infest damp, dark places like bathrooms, laundry rooms, basements, attics, and garages. They prefer room-temperature areas with 70–90% humidity.

Food source

These pests feed on carbohydrates, with a preference for sugar and starch. Unfortunately, that means their destructive feeding habits spell damage to clothing, books, newspapers, wallpaper, insulation, cardboard, tissue, envelopes, and food like oats and cereal. Unfortunately, silverfish can survive for weeks without food or water.

Signs of an infestation

Tell-tale signs include visible silverfish scurrying into cracks and crevices at night, holes in papers, yellow stains on clothing or upholstery, and small, pepperlike pellets of feces.

How to Prevent Silverfish

As with most pests, the best defense is a good offense. There are several measures you can take to help prevent a silverfish infestation. Following these steps will make your home less hospitable to these nuisance pests. Moisture prevention is key.

  • Reduce food sources: Store dry goods, including cereals, oats, grains, flour, andpasta, in tightly sealed containers.
  • Purchase humidifiers: Set them up in damp places like basements to limit the moisture that attracts silverfish.
  • Repair pipes and drains: Leaks can lead to excess moisture, which will draw out silverfish.
  • Seal entry points: Using caulk, seal up any cracks in your foundation, walls, and ceilings, and behind baseboards and windows.
  • Vacuum: Go over your carpets and upholstery thoroughly with a vacuum to make sure there are no crumbs that could draw silverfish.
  • Clean gutters: Keeping your gutters clean will help make sure that water drains away from your house instead of collecting.
  • Remove anything stored against your home: Items stored against your home can make it easy for silverfish to climb into your home through vents, pipes, or window and door frames.
  • Clean your shingles: Clean and seal your shingles to prevent access to silverfish.
  • Handle moldy wood: If you have any moldy wood, either repair it or get rid of it.
  • Store books and magazines carefully: Avoid storing lots of paper in moist, humid areas that silverfish seek out, like basements and garages.

How to Get Rid of Silverfish

The best way to get rid of silverfish is hiring a professional pest control company. You can look into traps and insecticides, but in general, these will only treat the individual silverfish that come across them, and not address a full infestation. To effectively eliminate silverfish, you must get rid of all of the pests and make their shelter inhospitable. Experienced pest control specialists can create an effective treatment plan.

Frequently Asked Questions

Is it bad to have silverfish?

Silverfish will not cause people any harm, but they can damage books, upholstery, clothing, wallpaper, insulation and more.

Why do you get silverfish?

Silverfish may come to your home in search of moisture and food. Highly humid areas in your house, like your basement, laundry room, or bathroom, are attractive to silverfish.

How do you get rid of silverfish?

You can try using store-bought insecticide, or silverfish traps that poison the pests. However, these methods are inefficient for large infestations. In that case, consider calling a pest control company.

Are silverfish a sign of a dirty house?

Not necessarily, but silverfish are more likely to inhabit homes that have food and crumbs out and excessive paper clutter.

Our Rating Methodology

The This Old House Reviews Team backs up our pest control recommendations with a detailed rating methodology that we use to objectively score each provider. We review pest control plans, navigate the provider website, speak with customer service representatives by phone and online chat (if available), request quotes, and analyze customer reviews for each provider. We then score the provider against our review standards for plans and services, reputation and customer responses, customer service offerings, workmanship guarantees, financing, and availability to arrive at a final score on a 5-point rating scale.

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