How to Kill, Control & Prevent Silverfish

What Are Silverfish?

Silverfish are small insects with silvery scales that rub off easily, so if you squish one, it will most likely leave a gray smudge on the surface. Silverfish are wingless, but they can move pretty quick, climbing up walls and winding their way around obstacles with ease. Because they need humidity to survive, these nocturnal pests like to hide in damp, dark places like bathrooms and attics.

Silverfish like to feed on starchy materials, such as wallpaper, books, loose paper, and even cereal. While mostly harmless to people, they can cause damage to the items they feed on. Aside from seeing silverfish crawling around, you may also notice damaged pages in books, book spines, or papers, small holes in clothing made from natural fibers, or yellow stains on walls, fabrics, or other surfaces.

What Do Silverfish Look Like?

If you flip on the light in your bathroom and see little gray bugs running for cover, there's a good chance they're silverfish. Here's how to identify them: 

• 6 legs
• 2 long antennae
• Thin, oval-shaped tapered body covered with silvery scales
• A long, antennae-like tail with 3 prongs
• Typically ½ to 1 inch long

How to Get Rid of Silverfish

Getting rid of these insects can be challenging, but persistence and using multiple control options will help get silverfish out of your house.

1. Eliminate their food supply. Since silverfish feed on starchy materials, the first step is to get rid of anything they might eat. Start in the pantry and put grains, flours, cereals, and even pet foods into airtight containers made from glass or hard plastic. Then, organize loose papers, mail, newspapers, magazines, and any other paper materials that might be lying around, getting rid of the ones you don't need. Recycle them, along with paper bags, at your local recycling facility. As an added precaution, consider protecting important papers and documents by storing them in resealable plastic sleeves or containers.
2. Control humidity. Silverfish prefer dark, humid environments, so you're most likely to find them in bathrooms, attics, and basements. Control humidity in these areas by installing dehumidifiers where possible, making sure there is adequate ventilation, and inspecting for leaks and water damage.
3. Seal cracks and crevices. Their thin bodies make it very easy for them to scurry behind light fixtures and electrical outlets so they can hide in your walls and ceilings until it's time to feed again. Seal them up, as well as any other holes and cracks in your siding, screens, window frames, and near plumbing.
4. Create a barrier. Treat baseboards and around windows and entryways inside your home with Ortho® Home Defense® Max Indoor Insect Barrier. It will create a long-lasting bug barrier for up to 12 months (indoors on non-porous surfaces). You can also apply it to the perimeter of your home. Always follow the instructions on the label.

Even though silverfish might be a nuisance to you now, they're certainly not something you have to live with. By following the steps above, they won't be a problem for much longer.

If you're having trouble with other insects in your home, check out How to Get Rid of Bugs Indoors.