Have you seen shimmering, creepy crawlers in your home, especially at night? Maybe you have silverfish. They’re harmless insects (not fish), but they can infest your home. Silverfish aren’t limited to a certain region of the country. They’re found around the world.
What Are Silverfish?
Silverfish are shiny, silver, wingless insects with antennae. They’re covered in fine scales that make them look like a fish. A firebrat is a similar-looking insect, but it is usually darker and mottled grey.
They have soft, flat, and oval-shaped bodies. Adults are usually about 3/4 inch long with two antennae on their heads and three tail projections.
Silverfish like the dark. They hide during the day and avoid direct sunlight. If you move an object they are hiding in or under, they will dart out very fast and find another dark hiding place.
Female silverfish lay eggs daily after reaching the adult stage. They lay eggs in crevices and cracks around your home, which hatch anywhere from three to eight weeks. Young insects reach the adult stage within four to six weeks.
Young silverfish look like adult silverfish, but they’re smaller and white. These insects live a long life, anywhere from two to eight years. They can also survive a long time without food, sometimes up to a year. However, they are sensitive to moisture and need high humidity to survive.
Silverfish grow in damp, dark, and cool places. Large populations can grow in new buildings with wet brick and stone. You might also commonly find them in:
- Basements
- Sinks
- Bathtubs
- Closet shelves
- Behind baseboards
- Bookcases
- Behind windows
- Behind door frames
- Laundry rooms
What Do Silverfish Eat?
Silverfish and firebrats are chewing insects and general feeders. They eat carbohydrates and protein, including:
They also eat nonfood items, some of which come from plant material:
Glue. Silverfish eat the glue in wallpaper, book bindings, carpet, curtains, and furniture coverings.
Paper. They prefer starchy materials such as paper and wood. Some reports suggest they have a preference for glazed paper with a starchy coating or a glossy, smooth finish. They might eat some of your books and magazines.
Linens. Because silverfish like starch, any starched linens are prime food sources. They might eat your linens, curtains, furniture coverings, and anything made of silk or cotton.
Sometimes, they get into a home in cardboard cartons, boxes, papers, and books that come from infested places.
Are Silverfish Harmful?
These insects are generally nuisance pests. Silverfish themselves won’t make you sick, but they can contaminate your food. They leave their poop behind in food, so make sure to check for any insects. Discard anything that has bugs in it.
Do silverfish bite?
Silverfish won’t hurt or bite you, so you don’t need to use insect repellent on your skin. However, they can be destructive. Because they are chewing insects, they can eat through your belongings. Their poop will also cause stains.
How to Get Rid of Silverfish
Silverfish are as common as cockroaches in some states. It can be very difficult to manage an infestation. It’s usually best to use the following methods together for the best results:
Seal your food. Reduce food sources for the silverfish. Keep all food sealed in airtight containers, especially flour, pasta, and pet foods.
Vacuum regularly. Vacuum carpets, floors, and furniture regularly, and clean up any food debris. Try to keep food confined to one area of the house.
Dehumidify and get rid of standing water. Silverfish love humidity and water. Use a dehumidifier to lessen moisture in damp areas of your home, such as the basement. Keep showers, tubs, sinks, and your laundry room clean and dry. Use plastic sheeting on the ground in any dirt crawl spaces and attics.
Make sure to maintain your house and yard. Keep your yard in good shape to allow water to drain away from your house. Keep your house in good condition with clean gutters and good seals around pipes and windows. Move lumber piles and garbage away from your house.
Fill cracks. Silverfish lay eggs in cracks and crevices. Seal off or caulk any cracks in your home to stop them from laying eggs and from hatching.
Use insecticides
- Dry products. Diatomaceous earth, boric acid, and amorphous silica gel are natural insecticides. Sprinkle these in areas where you normally don’t visit, like crawl spaces and attics. You can spray boric acid into cracks. These products work best if they stay dry.
- Sprays. Bait traps aren’t very useful for silverfish, but spraying them directly is effective. Pyrethrins are short-contact sprays made from flowers. They’re best used at night when the silverfish are active. Focus on cracks and places where you often see the bugs. Always read the product labels and follow the directions. If you have a heavy infestation, an exterminator can use sprays that’ll protect your house for several weeks.
- Japanese cedar essential oil. Made from the sugi plant (Cryptomeria japonica), this essential oil has been shown to repel or kill silverfish. Place a few drops on paper or cloth and place it near books or linens you want to protect. Keep it away from pets or ask your vet if it’s safe to use near your animals.
Remember that some insecticides are poisonous and toxic to the environment. Always read the labels and follow directions closely, especially if it recommends wearing gloves, masks, or covers over your clothing. Keep such products away from children and pets. Contact a professional pest control company to help deal with major infestations.
Takeaways
Silverfish won’t harm you, but they could harm some of your belongings. They feed on paper, glue, and linens. They also eat dead insects or foods you may have in your kitchen. They like to live in dark, damp places, such as basements. You’ll likely notice them at night or when you disturb them. If you have them in your home, there are actions you can take to get rid of them.
Silverfish FAQs
Can silverfish cause allergic reactions?
Silverfish don’t bite, so they don’t cause an allergic reaction that way. But they do shed their scales and leave droppings. Like with dust mites, those materials contain protein that may cause allergic reactions, such as a runny nose or itchy eyes.
Are silverfish harmful to cats or dogs?
No, silverfish don’t harm cats or dogs. They do not bite or sting, and they don’t burrow into their skin. A darting silverfish does look like a fun cat toy, though. If a cat (or dog) happens to eat a silverfish, don’t worry. Silverfish are not poisonous.