Silverfish Infestation

Follow these steps to get rid of a silverfish infestation!  Dont call an exterminator before trying our advice.  We also recommended traps that can be purchased on Amazon.

Here an outline of the topics covered:

How Do I Know if I Have Silverfish?

silverfish on floor

Since the creatures hide in dark crevices during the daytime and are only active at night, homeowners should rely on other methods of detection than simply looking for the insects.

Stains

Silverfish leave yellowish stains on floors, papers, or fabrics.

Holes

They also chew uneven holes on edges of paper and fabric products.

Molting

As the insects grow, they molt and leave behind discarded husks of dead exoskeletons that can accumulate and give a clue to their presence.

Feces
The insects also produce visible fecal matter that will be located near many of the potential food sources.

Bugs in Sinks & Tubs

Since silverfish are not good climbers, they can sometimes be found trapped in sinks or bathtubs when they fall in and cannot get out.

 

 

Why Are They In My Home?

Silverfish typically come into houses through small cracks or crevices seeking cool, moist environments, like those found in basements and bathrooms.

The tiny insects are less than a quarter-inch long and can squeeze through small spaces around doorframes, windows, baseboards, and cracks where wires and pipes enter houses.

They can also hitch rides on infested boxes containing clothing or books. Silverfish may infest newly built homes as well, drawn to the humidity released by drying plaster.

Preferred Habitat

Dark basements, storage closets, and bathrooms where local humidity regularly reaches upwards of 75 percent are ideal nesting areas for silverfish. They feed on anything from books and clothing to glue and flour.

The insects thrive at temperatures below 80 degrees Fahrenheit and live for several years at a time, producing up to 100 offspring every year.

What Problems Do They Cause?

Well-established silverfish populations can be extremely difficult to eradicate since the tiny insects are so persistent. In large numbers, they can do serious damage by chewing through books, wallpaper, clothing, and stored foods.

They eat dry substances, particularly those rich in protein, sugar, or starch, including pet food, cereal, pasta, dead insects, paper, and paste. As such, silverfish often target wallpaper and book bindings as meals.

Since they have weak mandibles and cannot actually bite, the pests scrape at their food. This method of feeding manifests as irregularly shaped holes spaced out in chaotic patterns along the surface of silverfish food sources.

Since silverfish require heat and humidity to survive, they congregate in bathrooms, basements, crawl spaces, wall voids, under kitchen sinks, and in laundry rooms. While they will travel around homes at night looking for sustenance, silverfish destruction is likely to be most apparent in their favorite nesting areas.

Since their consumption of wallpaper and destruction of books causes grief and costs property owners money, it is important to remove these pests at the first sign of activity.

How Do I Get Rid of Them?

Step 1: Sanitation

First, start with these simple steps to help sanitize your home from the bugs.

  • Vacuum cracks and crevices to remove dust and lint.
  • Clean bookcases by dusting and shaking out books.
  • Reduce the humidity with a dehumidifier.

Anhydrous calcium carbonate, a dehydrating agent, is effective in removing moisture from the air in closets and other small spaces.

Anhydrous calcium carbonate
40 Reviews
Anhydrous calcium carbonate
  • LABORATORY GRADE || Ideal for teaching and educational labs
  • APPLICATIONS || Used as a desiccant or source of calcium ions in solution
  • SAFETY & STORAGE || Includes GHS-compliant label printed with safety and storage information
  • COLOR-CODED CAPS || Bottle cap color matches the storage requirements for convenient visual reference

Step 2: Exclusion

Next, you need to “silverfish proof” the house so that they cant get inside.

Moisture

Large populations of silverfish point to more pressing issues in homes, such as the presence of leaky pipes or improper drainage. If the underlying humidity problems are not resolved, homeowners are likely to face a resurgence of silverfish even after successfully trapping significant numbers of the insects.

Entry Points

Common entry points include cracks in foundations or gaps in both windows and doors. Other times, the insects enter homes as stowaways in boxes affected by moisture or even during construction due to drying plasters and green lumber.

Here are some things that you should do to keep them out:

  • Don’t allow piles of old papers and magazines to accumulate.
  • Check old books before bringing them into the house.
  • Store garments, especially starched linens, in sealed plastic bags.
  • Seal cracks and crevices with caulking compound to reduce the number of hiding places.

Step 3: Killing Them

Below are the top three ways to kill them, if you want to DIY and not call an exterminator.

Traps

Homeowners can combat the presence of these insects by laying out traps. Since silverfish cannot fly and must scuttle across the ground, sticky traps are a means of catching individuals and reducing overall numbers.

Small glass jars with masking tape wrapped around the outside make viable homemade traps because silverfish are not able to climb the slick surface of the jar’s interior and become trapped once they fall inside.

However commercial traps are a good place to start.  Here are a few affordable options that you can try from Amazon:

Sale
Greenway Silverfish Traps
1,291 Reviews
Greenway Silverfish Traps

  • catches spiders & silverfish
  • glue based sticky trap
  • easy to use

EcoPest Glue Traps
740 Reviews
EcoPest Glue Traps

  • scented but non toxic
  • EcoPest has a good reputation for customer service
  • adhesive cardboard

Liquid Insecticides

Although liquid, dust or bait formulations can be used for silverfish and firebrat control, liquids are usually preferred in exposed areas of the home where dusts or baits may present a hazard to homeowners or pets.

Pest control companies usually use the following chemicals, but its not very easy to get these for household use:

  • propoxur
  • chlorpyrifos
  • bendiocarb

A good alternative is to use a pyrethrin (resmethrin, allethrin) spary.

Pyrethrins irritate the insect which causes them to run over an area on which a residual spray has been applied. Pyrethrin aerosols are conveniently available in grocery stores, hardware store, etc. Below are two good options that you can get on Amazon.com.

Sale
Shockwave1 Aerosol
321 Reviews
Shockwave1 Aerosol
  • Flushes and kills labeled pests, including cockroaches
  • Dual killing agents
  • Contains NyGuard IGR
  • Can be used indoors and outdoors
CB-80 Extra Spray
302 Reviews
CB-80 Extra Spray

  • Professional grade
  • Kills many bugs quickly
  • Safe for pets after drying

Residual insecticides usually provide 15-45 days of control and should be applied to the areas where the silverfish and firebrats are most commonly seen. Because both insects prefer to hide or rest where there are tight cracks or crevices, particular attention should be given to injecting small amounts of insecticide into cracks and crevices formed by shelving, loose moldings, or floor tiles.

Spray around baseboards, door and window casings, bookcases, shelving, closets, and in other storage areas, and places where pipes go through walls or floors. Spraying only the warmer parts of the building is usually sufficient to control firebrats.

Dust Insecticides

Dusts provide exceptional control of silverfish and firebrats, although they are more visible and can move from the original site of application. As a consequence, dusts can be used effectively in attics, dry crawl spaces, basements, and other places where their use is not potentially hazardous.

Commonly used dusts currently registered for silverfish and firebrat control are insecticides such as:

  • amorphous silica gel
  • boric acid
  • bendiocarb
  • diatomaceous earth
Sale
Dekko Boric Acid Packs
440 Reviews
Dekko Boric Acid Packs

  • place 2-3 packs in effected areas
  • easy to conceal because they are flat
  • takes about a week to work
  • used by professional exterminators

Harris Diatomaceous Earth Powder
7,456 Reviews
Harris Diatomaceous Earth Powder

  • Great for killing silverfish inside walls</li>
  • Works within 48 hrs
  • Works for a very long time (after all it’s just a powder), just keep it dry

Safer Home Diatomaceous Earth
23,941 Reviews
Safer Home Diatomaceous Earth

  • Kills many types of bugs
  • Silverfish will dehydrate and then die
  • SH51703 OMRI Listed

Pyrethrin dusts can be used but have shorter residual activity. Dusts are best applied with a hand duster, although boric acid dust can be obtained in an aerosol formulation.

Inject dusts into cracks, or spread a thin film wherever the appearance of the deposit will not be objectionable.

Regulations governing the use of pesticides are subject to constant change. Therefore, it is important to use the insecticide only as specified on the label.