Are Silverfish Harmful? How to Get Rid of Them Permanently

Silverfish are among the most common household pests, yet they remain some of the most misunderstood. These small, silvery, carrot-shaped insects dart across floors, hide in bookshelves, and thrive in bathrooms and basements. For many homeowners, their sudden appearance sparks questions: Are they dangerous? Do they bite? How do I get rid of them for good?

In this article, we’ll explore what makes silverfish tick, whether they pose any health or property risks, and most importantly, how to eliminate them permanently and prevent their return.

What Are Silverfish?

Silverfish (Lepisma saccharinum) are wingless insects known for their metallic appearance and fish-like movement. They measure about ½ inch to 1 inch long and prefer dark, damp, and humid environments. These nocturnal pests feed on starches, sugars, and proteins, which makes homes, especially bathrooms, kitchens, and storage areas, ideal habitats.

They are extremely resilient, capable of living up to a year without food, and surviving in temperatures ranging from 70°F to 90°F, with humidity levels above 70%.

Are Silverfish Harmful?

The short answer is: not directly harmful, but they can still cause problems.

1. Silverfish Do Not Bite or Sting

Silverfish do not bite humans, sting, or transmit disease. They have no venom, and they do not attack pets. Their jaws are designed for scraping, not biting skin.

If you see small red marks on your body, they are not caused by silverfish.

2. They Are Not Known to Spread Illness

Silverfish are not vectors for bacteria or viruses. They do not contaminate food the way cockroaches or rodents do. While they may crawl into cupboards or drawers, they are not considered a direct health hazard.

3. But They Can Damage Household Items

This is where silverfish become problematic.

Because they feed on carbohydrates and proteins, they can damage:

• Books (paper, glue bindings)
• Wallpaper (starch adhesives)
• Documents and photographs
• Cardboard boxes
• Clothing made of cotton, silk, linen, or wool
• Food items like cereal, flour, oats, and sugar
• Stored items containing adhesives, such as photo albums or crafts

Over time, an untreated infestation can ruin important paperwork, sentimental items, or expensive textiles.

4. They Are a Sign of Moisture Problems

Silverfish thrive in humid environments.

If you see many silverfish, it can indicate:

• Poor ventilation
• Water leaks
• High bathroom or basement humidity
• Damp storage areas

Left unresolved, moisture can lead to mould growth or structural damage, problems more serious than the insects themselves.

Why Do Silverfish Enter Homes?

Understanding why silverfish invade can help you eliminate them.

1. Moisture

Silverfish need high humidity to survive. Bathrooms, laundry rooms, basements, attics, and kitchens are their hotspots.

2. Food Sources

They feed on:

• Starch
• Sugar
• Protein
• Dead skin cells
• Hair
• Paper and glue
• Fabric fibres

Crumbs, dust, and clutter supply a constant food supply.

3. Hiding Spots

Silverfish love tight, dark crevices, behind baseboards, under sinks, inside storage boxes, and around drains.

Once they establish themselves, they can reproduce quickly, laying eggs in hidden, protected areas like cracks and wall voids.

How to Permanently Get Rid of Silverfish

Eliminating silverfish requires a mix of eradication, prevention, and environmental changes. Because they are tough and fast-breeding, relying on a single method rarely works. Below is a comprehensive step-by-step approach.

Step 1: Reduce Moisture

Silverfish cannot survive long in dry environments.

How to lower humidity:

• Use a dehumidifier in basements, laundry rooms, and bathrooms.
• Install ventilation fans where moisture accumulates.
• Fix leaky pipes, faucets, or drains.
• Improve airflow by opening windows or adding vents.
• Avoid leaving wet towels, sponges, or damp laundry sitting out.
• Use desiccants (like silica gel or DampRid) in closets, cabinets, and storage areas.

Reducing humidity alone often cuts the silverfish population dramatically within weeks.

Step 2: Remove Food Sources

Cutting off food sources makes your home less inviting.

What to do:

• Store cereal, flour, oats, pasta, and sugar in airtight containers.
• Vacuum floors, carpets, and baseboards regularly to remove crumbs and dead skin cells.
• Dust shelves, especially around books and papers.
• Keep clothing clean and sealed during long-term storage.
• Declutter areas where paper or cardboard accumulates.

Step 3: Seal Entry Points and Hiding Spots

Silverfish hide and lay eggs in cracks, crevices, and wall voids.

Caulk or repair the following:

• Gaps around baseboards
• Cracks in the walls
• Spaces near plumbing fixtures
• Gaps around electrical outlets
• Loose wallpaper edges
• Unsealed attic or basement joints

Use caulking, weather stripping, and sealant foam where necessary.

This not only restricts their movement but also prevents new arrivals.

Step 4: Use Natural Remedies (Safe & Effective)

If you prefer non-chemical solutions, try these:

1. Diatomaceous Earth (DE)

This natural powder dehydrates and kills silverfish.

• Sprinkle a thin layer around baseboards, behind appliances, or in cupboards.
• Leave for 24–48 hours.
• Vacuum thoroughly.

Ensure you use food-grade DE.

2. Boric Acid

A common DIY remedy. It kills silverfish by disrupting their digestive system.

• Use lightly along cracks and edges.
• Keep away from children and pets.

3. Cedar Oil or Cedarwood

Silverfish dislike the smell.

• Use cedar oil sprays.
• Place cedar blocks in closets or bookshelves.

4. Cloves or Clove Oil

Their scent repels silverfish.

5. Traps

You can use:

• Sticky traps
• Homemade traps (a jar wrapped in tape with a bread crumb inside)

These reduce populations and help identify hotspots.

Step 5: Use Chemical Insecticides

If natural methods don’t work or the infestation is heavy, insecticides may be necessary.

Common chemical options:

• Pyrethrin-based sprays
• Permethrin dusts
• Baits designed for silverfish

Apply only in crevices, cracks, and hidden areas according to label instructions.

Avoid overusing chemicals. Silverfish do not live on open floors but in protected hiding spots.

Step 6: Call Professional Pest Control

If silverfish are appearing daily or causing visible damage, professional help may be the fastest long-term solution.

Pest control companies can:

• Identify exact hiding locations
• Treat wall voids and deep spaces that homeowners can’t reach
• Provide humidity inspection
• Seal structural gaps
• Apply long-lasting insecticides safely

This is especially recommended for multi-story homes, older houses, or buildings with chronic humidity.

How to Prevent Silverfish From Returning

Getting rid of silverfish is only half the battle; you must also prevent future infestations.

1. Maintain Low Humidity

Use dehumidifiers in damp seasons and ventilate rooms properly.

2. Keep Food Sealed

Dry goods should always be in airtight containers.

3. Clean Regularly

Dust and vacuum weekly, especially around baseboards and bookshelves.

4. Rotate Stored Papers and Clothing

Silverfish love undisturbed places. Moving your items occasionally disrupts them.

5. Fix Leaks Quickly

Water attracts silverfish more than anything else.

6. Manage Clutter

Stacks of paper, cardboard boxes, old magazines, or stored textiles create perfect habitats.

Conclusion

Silverfish are not harmful to humans not bite, do not sting, and do not carry diseases. However, they can damage books, clothing, food, and important documents. More importantly, they often indicate a humidity or moisture issue in your home.

The best way to permanently eliminate silverfish is to reduce moisture, remove food sources, seal entry points, and use traps or treatments as needed. For severe infestations or recurring problems, professional services such as SWAT Pest Control Brisbane can offer fast and effective long-term solutions.

 Title: Are Silverfish Harmful? How to Get Rid of Them Permanently

Meta Desc: Discover if silverfish are harmful and learn effective, permanent ways to get rid of these pests from your home for good.