Silverfish

How to Identify and Get Rid of Silverfish

Silverfish (Edited)
Christian Fischer/Wikimedia Commons

Rate this Article: 

Average: 4 (25 votes)

The Summer Solstice is Friday. Get ready!
Here are 10 things you should know about the first day of summer.

LEARN MORE

Half-eaten pages in your books? Chewed-through boxes in your pantry? These are signs of a silverfish infestation. Here’s how to identify, get rid of, and prevent silverfish infestations in the home.

What are Silverfish?

The silverfish (Lepisma saccharina) is a small insect pest found around the globe. They are considered a nuisance pest, meaning that they are neither harmful to humans nor spread disease. Instead, silverfish are known for damaging material goods, such as books, wallpaper, photos, clothing, and dry foods in the kitchen pantry.

Silverfish are particularly attracted to under-sink areas in the bathroom or kitchen, where the environment is humid and dark. They may also live in walls, closets, or crawl spaces. They remain hidden during the day, but at night, they emerge to forage for food. 

A similar insect pest, the firebrat, looks and behaves much like the silverfish. Both pests can be controlled using the same techniques.

Silverfish

Fun Fact: The latter half of the silverfish’s Latin name, saccharina, refers to the insect’s fondness for eating materials made of polysaccharides (complex carbohydrates), such as cellulose and starch, which are found in paper products, fabrics, and foods. 

Identification

How to Identify a Silverfish

Silverfish are small insects with long, thin, carrot-shaped bodies. They typically reach no more than three quarters of an inch in length and have a silvery-gray coloration. Their bodies have no obvious segmentation, and adults are covered with thin scales resembling those of a fish. They are easily identified by the two long antennae stemming from their heads and the three tail-like appendages on their back-ends. They are smaller and thinner than cockroaches, and a different color than the similarly-sized earwig.

Silverfish have rather stubby legs, but don’t let that fool you. They are capable of moving very, very quickly, especially when startled. This is when most people see silverfish: when the pests’ late-night feasting is interrupted and they scurry back to the dark corners of your home. Their rapid side-to-side movement resembles a swimming fish, which is said to be the source of their name.

Silverfish Damage

Practically any material containing carbohydrates or proteins is susceptible to silverfish damage. Bookbinding glue and wallpaper paste are common targets. Often, silverfish won’t eat all the way through a material, in which case it will look like just a thin layer has been scraped off (see photo, below). Silverfish also feed on non-synthetic cloths, such as cotton or linen, evidenced by tiny, unconnected holes in the fabric.

Silverfish damage in a book. Photo by Micha L. Rieser/Wikimedia Commons.
Silverfish damage in a book. Photo by Micha L. Rieser/Wikimedia Commons.

Though silverfish usually stick to more humid places, they may also invade the kitchen pantry and target flour, cereals, and other grains. 

Control and Prevention

How to Get Rid of Silverfish 

  • Sticky traps, which consist of a cardboard base and a thin layer of sticky glue, can be effective at controlling small populations. Place traps in areas where silverfish activity is high. The insects will get stuck to the glue as they attempt to move across the trap. We recommend only using sticky traps that contain a pesticide in the glue, as this will prevent a trapped insect from suffering for too long needlessly.
  • Use dehumidifiers to dry the air in rooms where silverfish are seen, especially in the bathroom. Also ensure that under-sink areas in the kitchen and bathroom, as well as closets and cellars, are well ventilated.
  • Diatomaceous earth (DE)—a powder made up of tiny silica particles—can be effective. The particles act as an irritant and dehydrate insect pests as they come in contact with the powder. Spread DE around areas where silverfish have been seen, and around potential pest entry points, like cracks in the wall or furnishings.
  • Pyrethrin, a natural insecticide, is derived from chrysanthemum flowers and can be used to control silverfish. Its synthetic equivalent, permethrin, is generally more effective, as it does not break down as quickly when exposed to light and moisture. Warning: Both pyrethrin and permethrin are extremely toxic to cats!
  • There are a number of commercial pesticides that can be used to control silverfish. Always read a product’s label before use to determine that it is safe for your household.

How to Prevent Silverfish 

  • Silverfish enjoy humid places, so making sure that under-sink areas in the kitchen and bathroom are well ventilated can be an effective deterrent. Use a dehumidifier, if necessary.
  • Sealing gaps and cracks in your walls and floor will cut off entry points for the pests.
  • The strong scents of cinnamon and cloves are said to repel silverfish. Keep small amounts of these spices in areas where you commonly see the pests to help keep them at bay. 
  • Do not leave crumbs or food scraps out in the open, as they can attract silverfish (and other pests!).
  • Store precious documents and clothing in air-tight, plastic containers to keep silverfish from damaging them. 

Do you have any tips for preventing or stopping silverfish infestations? Tell us in the comments below!

Founder's Warehouse Sale

2020 Almanac Calendar Club

Reader Comments

Leave a Comment

silverfish abatement

I line all my clothes closets, linen cabinets etc. with cedar...works like a charm. works in drawers and boxes out in the garage. I usually put down some paper or tissue if I'm putting clothing on top of the cedar. I have no problem with the little buggers!

saving books

Does anyone have experience with protecting old books from silverfish? I use bay leaves right now. I am thinking that putting DE or cinnamon around the books could get messy.

Silverfish

Another type of Bay Leaves kills insects and that is laurel leaves. They look like bay and are a type of bay. They contain cyanide so don't put them where you can smell them or you'll get a sore throat. I used to collect bugs as a kid and used them in my killing jar.

Silverfish

People have approached me (ex-Pharmacist, retired) about these and I often tell them they're quite pretty and if they're somewhere they can do no harm then treat them as a pet! It does beg the question though: why are people so hell bent in getting rid of spiders in the home?

Silverfish

My Grandmother always used Borax powder to get rid of silverfish. A big box is reasonably priced and I suspect that it works the same way as the DE powder does. I have used this up in my attic where I have seen these nasty critters. I poured it on the long beams around the perimeter of the house. I don't know if I got rid of all of them but I don't see many anymore in the living area. I also put the borax in the back of my cabinets in the kitchen and along the wall behind my dishwasher and stove. I poured it in a line in front of the dishwasher and used a hairdryer to blow it under to get it to the wall. Worked like a charm.

Borax for pest deterrent

I too have successfully used borax as a cost effective pest deterrent for silver I should, ants, etc. Works very well. It dehydrated them and you just vacuum it up. If you mix borax in sugar water the ants eat it, take it back to the colony and eliminates them all.

Silverfish In Fabrics

I appreciate this comment about using Borax to handle the "Invasion of Silverfish" and other insect pests. Silverfish are in hog heaven on cotton and linen fabrics that have been sprayed with aerosol starch while ironing. They lay their eggs in or on a substances where there is a guaranteed food supply for their young. "Sizing" applied by fabric manufacturers to keep their cotton and linen fabrics crisp and appealing to the consumer, is another substance that silverfish feed on.
I, like the majority of Quilters, have an abundance of fabrics in my stash or trove of goods. I also have a cache of hundreds of magazines as well as books, that I've purchased used from local charity thrift shops; garage and tag sales; and online. I consider calling fabric, threads and reading materials "used" if they were not purchased from a retail store. There are no assurances that the fabrics have not been in the presence of insects like silverfish, and usually one who is buying preowned fabrics, wouldn't consider asking about silverfish. Most buyers are concerned with damp, mildew basement or tobacco odors. And if the thought or hint of insects being anywhere near the fabrics, it's usually cockroaches that come to mind.
I do not launder my fabrics before I use them. So, in order to prevent any outbreak of of infestation from eggs layed in the fabric folds, I always place purchased fabrics in a plastic zipper bags used for food storage just as soon as I'm able too. Until then, the purchases remain in my garage until I place them in the bags for my sewing room. It's not enough to keep fabrics in plastic tote containers, insects are able to wiggle in and out of the tote's lids. I use small quart sized zip lock bags or sandwich size zip lock bags for fat quarters. The 1 gallon sized zipper bags are adequate for 1-2 yards of folded fabrics. And the 2 gallon sized zipper bags are perfect for larger sized measures of fabric. My fabrics are not used as a display or decor items, so it matters little to me if they're kept in plastic.

I buy bulk sized quantities of these storage bags. And I reuse them after I've emptied the individual ziplock bags, and before I would use a new one. And I don't worry about moisture build up in the bags because it's not my intentions to save or collect fabrics. And should I have my own garage sale or tag sale, the fabrics are kept in the bags when I put them out for sale. It's an assurance that I provide to buyers, that indicate that I don't have an infestation in my sewing room.

I hope this information is helpful to someone who has more fabrics that they are able to use in the near future.

Pest & sticky glue strips

I'm all for getting rid of pest, no matter how. And if sticky glue strips do the trick, so be it.

Silverfish

I tend to see a lot of silverfish around my house. A home inspector advised me to get rid of wallpaper as much as possible throughout my home. I've done this and noticed it helped greatly. Apparently it's a delicacy for silverfish...

Glue traps

I am appalled that you would recommend glue traps to eliminate any pest. These are the most horrendous ways of dealing with "unwanted guests." No matter what the species, the creature, whether it is a silverfish or a mouse, gets stuck on the trap and spends a long time trying to get off it. In the meantime, it suffers greatly. Please to do not recommend these traps for any elimination of a pest.

Should a mouse, or other animal, get caught on a glue trap, it can suffer incredible pain in trying to free itself, as well as losing fur and sometimes skin. It may even try to chew off the appendage that is stuck. This kind of horror belongs only in horror movies, not people's homes. I beg you, please to not advocate the use of glue traps for any removal of a pest. There are better ways to get rid of silverfish, moths, mice, etc. I can not tell you how disturbed it makes me feel to think of a creature being stuck like this.

Sticky Traps

The Editors's picture

Thank you for expressing your concerns so passionately. We do NOT advocate the use of glue traps for vertebrate pests, such as mice and rats, under any circumstances. However, for invertebrate pests, there are sticky traps that contain pesticides, which ensures that the insect does not suffer for too long in the trap. We have edited the article to reflect this.

Sticky Traps

Always someone to complain. I would use it in heart beat. They are gross looking bugs.

Ant Traps work too.

I had an infestation in my garage of silver fish. I put out Ant Traps, that come already filled with insecticide and it killed all of the silverfish too, along with any ants that happen to come into the garage. I haven't had any since.

Glue traps

Oh good grief!!!! You bleeding hearts will be the destruction of the world. These pests are a health hazard to everyone. They make people & other animals sick (pain, death) so why be concerned with inflicting these pests. Get rid of these pests!

Silverfish

You are absolutely correct in your response! Thank you for your comment. I was thinking that I was the only person out here that really thinks.

Thank you again,

Josephine

FREE BEGINNER'S GARDEN GUIDE!

BONUS: You’ll also receive our Almanac Companion newsletter!

The Almanac Webcam

Chosen for You from The Old Farmer's Store