How to Get Rid of and Kill Silverfish Quickly
Learn how to get rid of silverfish infestations in your home with our spray & control kits
What Are Silverfish ?
Silverfish insects have flattened, long, slender, brown-silvery bodies that are broad at the front and taper gradually toward the rear. You can find silverfish in any part of the US. They prefer high humidity and are often found in areas associated with heat and moisture; commonly found in bathtubs. Silverfish can eat grains in your pantry or chew large holes in upholstery, clothing, or stored paper as a nuisance pest.
Prevent Silverfish Infestations
To prevent silverfish inside infestations, eliminate sources of excessive moisture in places like faulty plumbing and areas of condensation. Silverfish love the humidity. The use of a dehumidifier will reduce moisture content in the air that is essential to silverfish survival. Silverfish can not survive inside buildings in low relative humidity. Silverfish infestations may be difficult to control if the relative humidity is above 50% year-round in an air-tight house.
Other dehumidfy methods include:
- Ventilate closed rooms and attics
- Eliminate standing water
- Run an air conditioner
- Consider a bathroom fan in the shower area.
Reduce clutter and food sources
Reduce clutter and food sources. Regularly vacuum cracks and crevices around the home with a narrow tip. Remove easily accessible food sources such as flour, cereals, and pet foods by storing pantry food in tight containers to reduce food sources. They eat a wide variety of foods that have carbohydrates and proteins. They will eat dried beef, flour, starch, paper, dead insects, glue, paste, cotton, linen, and some synthetic fibers. Reduce clutter; silverfish may be found in the attic and basement areas in storage boxes. They eat the glue on the boxes and book bindings. They may feed on surface molds found on cardboard boxes found in damp basements or attics. Make sure that vents are open in the crawlspace.
Reduce Silverfish Infestations Outside
Silverfish may live outside under stones, rocks, leaf clutter, birds nests. They prefer warm temperatures. Remove any possible harborage areas such as leaf and grass litter near your home. Keep gutters cleaned out. It is helpful to use standard exclusion techniques such as caulking cracks and crevices, making sure screens are tight-fitting and the use of weather stripping around windows and doors.
Silverfish love to eat paper and glue so it stands to reason that they love cardboard boxes. Replace them with storage bins when practical.
Silverfish Removal with Insecticides
If you already have a silverfish problem inside your home, spray the home's perimeter with a residual insecticide. Spraying the inside perimeter with a narrow band helps kill silverfish as they move throughout the structure. Spraying the outside foundation wall will keep a variety of bugs from entering the structure, including silverfish. In addition, you can scatter an insecticide bait such as Intice Perimeter 10 in the attic.
Spray along the foundation wall with a two or three-foot band. Avesta CS and Cyper WSP last for two to three months. Both Avesta CS and Cyper WSP are odorless. The wettable powder (WP) formulation in the and Cyper WSP will leave a slight film that against dark surfaces. Avesta CS does not leave a film.
However, if you have a severe active infestation of silverfish, further action will need to be taken. Look at stored boxes and insulation in your attic as a food source for the silverfish. It is best to dust or bait these areas for greater control. When you use baits or dust, get it as close as possible to the silverfish habitat for maximum effect. Make sure that the bait and dust stay hidden from humans and pets.
Using Insecticide Dust
Both Cimexa Dust and D-Fense Dust last six months in areas protected from the elements such as attics. When applying insecticide dust to attics, pay particular attention to insulation. Also, make sure to cover storage boxes, light fixtures, and electrical outlets.
Apply the dust to any area that can be kept dry.
An easy way to apply D-Fense Dust and Cimexa Dust is to use an insecticide duster called the Dustin Mizer. The Dustin Mizer Duster is good for cranking out a large amount of dust quickly. You will want to use 1 lb of dust per 800-1000 square feet. For smaller dusting jobs, JT Eaton Bellow Duster works well.
Dust needs to be in hidden areas such as:
- Attic Insulation
- Behind Refrigerators and Ovens
- On Boxes
- Light fixtures
- Electrical outlets
- Underneath siding
Silverfish Removal with Insecticides
Intice 10 Perimeter Bait works very well against silverfish as well as roaches and crickets. It can be sprinkled out in a self-contained one lb.bag, in all the areas you believe they are hiding. Typical areas of baiting would be in the attic or crawlspace.
PT 221L Residual Insecticide Aerosol PT 221L Residual Insecticide Aerosol with a crack and crevice tip enables you to get behind baseboards and corners of the traveling paths of the silverfish. This type of aerosol is very helpful in bathrooms where silverfish like to eat the back of the wallpaper.
Silverfish are about 1/2 inch long, with a uniform silvery color over the top surface. Their bodies are long and slender. Silverfish are broad at their head with gradual tapering toward their rear.
Silverfish Diet and Signs of Infestations
Silverfish eat a variety of foods containing carbohydrates or proteins. This variety includes sugar, paper, starch, cotton, linen, glue, paste, rolled oats, dried beef, beef extract, and dead insects. Silverfish require a large supply of starchy foods or molds to survive. Silverfish diets are high in protein, sugar, or starch, including cereals, moist wheat flour, the starch in book bindings, and paper on which there is glue or paste. Silverfish can eat grains in your pantry or chew large holes in upholstery, clothing, or stored paper. As a nuisance pest, silverfish feed on wallpaper pastes, natural textiles, books, and papers.
- Silverfish are fast-moving and can travel throughout buildings. Once they find a good source of food, they stay close to it.
- Silverfish go through a three-stage life cycle called gradual metamorphosis, whereas most insects have a four-stage life cycle (complete metamorphosis). Silverfish can lay eggs at any time during the year. The eggs take 19-43 days to hatch. The life cycle from silverfish egg to adult is three to four months.
- Silverfish are nocturnal, but they are also active in dark areas throughout the structures they inhabit. They can be a problem year-round.
- You may see silverfish trapped in sinks and bathtubs because they enter seeking moisture and are unable to climb a slick vertical surface to escape.
- Silverfish may attack fabric if there are leftover food particles (spilled cokes and other starchy carbohydrates ) or areas of soiled substances (sweat). They will not eat the fabric for a substance like clothes moths but will damage the fiber trying to get to the substances on the fabric.
- Note: Attics are a favorite place for silverfish to inhabit due to the abundant food sources available from blown in paper insulation and storage boxes.
Silverfish Detection and Signs of Infestation
Silverfish can be found almost anywhere, but they prefer damp environments with moderate temperatures such as basements, laundry rooms, and under sinks.
Since Silverfish travel long distances looking for food, it may be challenging to know the exact source of silverfish infestations.
- Silverfish prefer dark and moist environments (75 - 97% humidity). Some of their preferred habitats are basements, kitchens, sinks, bathtubs, bookcases, closet shelves, behind baseboards, wall voids, and sub-floors.
- Silverfish molt throughout their lives. Finding their cast skin is a good indicator that Silverfish are present.
- Finding small irregular shaped holes in fabrics is a common sign of Silverfish. Irregularly shaped holes in wallpaper is another indicator because they like to eat the glue.
- Silverfish may leave a yellowish stain on the fabric. Firebrats will feed extensively on rayon, whereas Silverfish usually damage it only slightly.
- Outside, Silverfish may be found in nests. These nests can belong to other insects, birds, and mammals. They also live under tree bark and mulch. They are sometimes found in wood shingles or sidings on houses.
- Inside, Silverfish are found just about anywhere that is dark and humid.
Recommended Silverfish Control Insecticides and Dust
Written by our resident pest control expert Ken Martin.