Do Silverfish Bite? Uncovering the Truth About These Insects

Silverfish are small, wingless insects known for their distinctive, fish-like appearance and their silver or pearl-gray color. They have long antennae and three long, thin tail-like appendages at the end of their abdomen, giving them a unique appearance that often raises questions about their behavior, such as whether or not they bite humans.

Although silverfish might seem a bit intimidating due to their unusual look, the good news is that they do not bite humans. These insects are primarily scavengers, feeding on a wide range of items like crumbs, books, wallpaper, and even clothing. While they may be considered a nuisance due to their feeding habits and potential to infest homes, silverfish are not considered harmful to humans as they do not possess the necessary mouthparts to bite.

Do Silverfish Bite?

Bite Potential in Humans

Silverfish are small, wingless insects with a distinctive fish-like appearance. They have flat bodies, are generally 0.85 cm (0.33 in) in length, and are covered with tiny glistening scales1. Despite their peculiar appearance, silverfish do not pose a significant threat to humans. Due to their weak jaws, they are not known to bite humans. Instead, they primarily feed on starchy materials and cellulose found in items like paper, cardboard, and fabrics2.

Pets and Silverfish

Silverfish are not considered harmful to pets either. Their weak jaw structure isn’t designed for biting pets, and they prefer to feed on carbohydrate-rich sources like paper, books, and glue3. There is no evidence to suggest that silverfish are dangerous for animals like cats and dogs.

Comparison table: Silverfish bites in humans and pets

Aspect Humans Pets
Bite potential Very unlikely Very unlikely
Harmful No No
  • Features of silverfish bites

    • Weak jaws
    • Unlikely to bite humans or pets
    • Not harmful

In summary, silverfish are not harmful to humans or pets and are not known for biting them. Their weak jaws make them incapable of causing any significant damage.

Identifying Silverfish

Physical Characteristics

Silverfish, scientifically known as Lepisma saccharina, are small, wingless insects characterized by their silver or pearl-gray color and scaly body. Their glistening scales are often described as fish-like, which gives them their common name. On average, they measure 0.85 cm (0.33 in) in length and have two long antennae.

Notable features:

  • Silver or pearl-gray color
  • Scaly, glistening body
  • Wingless
  • Long antennae

Habitat and Behavior

Silverfish are nocturnal creatures that thrive in damp, dark environments. They are commonly found in areas with high humidity and moisture, such as basements, bathrooms, kitchens, and crawl spaces. They are also known as bristletails or fish moths.

Habitat preferences:

  • Damp, dark areas
  • High humidity
  • Basements, bathrooms, and kitchens

Their diet consists mainly of carbohydrates, like starches and sugars. They are particularly attracted to wallpaper, books, and fabrics, where they cause damage by feeding on the glue and fibers. Female silverfish lay clusters of eggs in hidden areas, making it challenging to locate and eradicate them.

Behavior traits:

  • Nocturnal
  • Feed on carbohydrates (starches and sugars)
  • Attracted to wallpaper, books, and fabrics
  • Lay clusters of eggs in hidden areas
Attribute Silverfish
Color Silver or pearl-gray
Body Scaly, glistening
Antennae Long
Size 0.85 cm (0.33 in)
Environment Damp, dark, humid
Diet Carbohydrates
Destructive Habits Wallpaper, books, fabrics

Signs of Infestation

Home Damage

Silverfish infestations can cause noticeable damages to your home. They are known to feed on various items such as paper, fabric, and some food items. Keep an eye out for the following signs:

  • Damaged paper or fabric with irregular holes
  • Contaminated food sources
  • Presence of scales, cast skins, or fecal spots

These damages may be subtle, but they can accumulate over time. It is essential to monitor any potential infestation signs to prevent extensive home damage.

Health Concerns

While silverfish are not known to bite or transmit diseases, they may still contribute to health concerns. Some possible issues include:

  • Production of indoor allergens
  • Triggering allergic reactions
  • Presence of a yellow residue from molting

While silverfish do not pose severe health issues, it is crucial to take action to prevent their infestation and maintain a healthy home environment.

Preventing and Controlling Silverfish

Maintaining a Clean Environment

One of the primary ways to prevent and control silverfish is to maintain a clean environment. Silverfish thrive in humid conditions, so using a dehumidifier can help reduce their presence. Regular cleaning practices also play a crucial role in silverfish control:

  • Vacuum often to remove dust, debris, and potential food sources.
  • Seal food in airtight containers to eliminate enticing smells.
  • Remove clutter to minimize hiding spots.

Natural and Chemical Methods

There are several natural and chemical methods available to control silverfish populations. Here’s a comparison table of some common options:

Method Pros Cons
Traps Non-toxic, affordable May not eliminate entire infestation
Insecticides Effective in controlling large numbers Can be toxic and harmful to the environment or other creatures
Sealing entry points Prevents more silverfish from entering Time-consuming, may not address existing infestation
Natural methods Environmentally friendly, non-toxic May not be as efficient as chemical methods

When choosing a chemical method, consider insecticides containing bifenthrin, cyfluthrin, tetramethrin, or phenothrin. Remember, these chemicals can be toxic and should be used with caution.

For a more eco-friendly approach, try natural methods like:

  • Diatomaceous earth: Spreading this powder in infested areas can kill silverfish by damaging their exoskeletons.
  • Lavender and cedar oils: Scented oils can repel silverfish and help prevent new infestations.

Lastly, seal any gaps or crevices around windows and door frames using caulking to block their entry points. Regularly inspect your home and address any potential entry points or hiding spots to maintain an effective pest control strategy.

Protecting Your Belongings

Proper Storage

Storing your belongings in the correct way is an essential step in preventing silverfish damage. Some items that silverfish commonly target include:

  • Books
  • Paper items (such as documents, magazines, and cardboard boxes)
  • Clothing (especially fabrics like silk and synthetic materials)

To protect these items, consider the following storage methods:

  • Airtight containers: Keep your belongings in sealed containers to prevent silverfish access.
  • Cedar: Store clothing in cedar chests or use cedar hangers, as the scent repels silverfish.
  • Avoid cardboard boxes: Opt for plastic bins instead, as silverfish are attracted to cardboard and the glue used in their construction.

Regular Home Maintenance

Routine maintenance within your home can also deter silverfish infestations. Pay attention to areas like attics, baseboards, carpets, and sinks, as these are common hiding places. Some suggested maintenance tasks include:

  • Sealing cracks and crevices: Ensure there are no gaps or holes for silverfish to enter.
  • Repairing leaks: Fix leaks around sinks and other water sources to reduce humidity and discourage silverfish.
  • Cleaning regularly: Regularly vacuum carpets and dust baseboards and shelves to eliminate potential food sources.

Below is a comparison table of two popular silverfish control methods:

Method Pros Cons
Diatomaceous Earth Effective, natural, and non-toxic Can be messy, needs reapplication after vacuuming
Boric Acid Highly effective and relatively low toxicity Not safe around pets or children, can damage surfaces

By following the suggested storage methods and regular home maintenance practices, you can safeguard your books, paper items, clothing, and other belongings from silverfish. While they’re not known to carry pathogens and rarely bite humans, it’s still essential to take preventive measures against these pests.

Footnotes

  1. (https://entnemdept.ufl.edu/creatures/URBAN/silverfish.HTM)

  2. (https://extension.umd.edu/resource/silverfish-and-firebrats)

  3. (https://apps.extension.umn.edu/garden/diagnose/insect/indoor/beetles/medium/silverfish.html)

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Silverfish

 

Help identifying a bug
Hi,
I attached a pic of the bug that has been plaguing my room. I found 8 huge ones around and under my bed (about 2″ long), and have found several smaller (0.5″) to bigger (1 – 2″) ones randomly in other parts of my room and in boxes. Could you please help me to identify it, and if so would you know any way to keep them from coming back? Thanks!
Kym

Hi Kym,
This is probably the most beautiful image of a Silverfish we have ever seen. If we could tell you how to eradicate the Silverfish from your home, we would be fabulously wealthy. They are found in dark warm places, and can squeeze through tiny places. They are found inside walls as well. They are generally considered household pests as they will eat starchy substances, including book bindings, fabric and wallpaper glue. They will also eat many food products including sugar, flour and cereals.

Letter 2 – Silverfish

 

Apparently we have roommates
Location: Yorba Linda, Ca
November 7, 2011 1:22 am
I find these guys everywhere. They hang out mostly in bathrooms and the kitchen. I find them mostly in our vanity drawers, bathroom counters, in cabinets, under dog bowls, in sinks and tubs but now I found one on one of my garments in my closet and I am getting concerned. My home is about 30 years old. Can you tell me whay they are?
Signature: Lucy

Silverfish

Dear Lucy,
We regret to inform you that you have an infestation of Silverfish, one of the most difficult household pests to eradicate.

Letter 3 – Silverfish

 

UCB- Unidentified Crawling Bug
Location: Charleston, SC
December 18, 2011 7:36 pm
Dear Bugman,
I see these little things crawling around, mainly on the first floor of our house. This is one of the biggest that I’ve seen. What is it?
Signature: Brian from Charleston

Silverfish

Hi Brian,
This is a Silverfish, a common household pest.  They will eat many stored foods and even some items not normally thought of as food, like the starch in book bindings and wallpaper adhesives.  Silverfish are generally found in damp, dark locations.

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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