Silverfish (Lepisma saccharina) and Firebrats (Thermobia demestica) are some of the most primitive insects still in existence today. They are also common pests in Ontario, and are feared because of their grotesque, creepy appearance. Both silverfish and firebrats are also referred to as ‘bristletails’ because of the long bristles at their tail.

These omnivorous scavengers are from the family Thysanura, and originated from the tropics. They have successfully adapted to Ontario weather by finding warm and damp habitats. Being quick, nocturnal, and capable of living without food for several months, make these insects resilient, and tough to discover before their populations grow.

Silverfish and firebrats find their way into homes and businesses by hitchhiking in on furniture, books, papers, pantry products, and cardboard boxes. Indoors they gravitate to cracks and crevices, basements, attics, basements, bathrooms, wall voids and crawl spaces. Both have been known to follow pipelines from basements to other lower-level rooms and take up residence in bookcases, closet shelving, and behind baseboards, window frames or door frames.

Once inside they feed on dead insects, food crumbs, glue, starch, wallpaper paste, and paper products. nests are commonly located near their primary food source. Predators of silverfish and firebrats include earwigs, spiders and centipedes.

What do Silverfish Look Like?

Silverfish are flat, slender insects with tapered teardrop or carrots shaped bodies. They have 6 legs, 3 body parts, chewing mouthparts, and average 1 to 2 cm in length. They are wingless, with large antennae, and three long bristles at their tail. Silverfish range in colour from white to brown-grey to blue-silver, and their bodies are covered with shiny silver scales that give them a metallic sheen. Silverfish are quick, and move in a wiggling motion that resembles a swimming fish.

                A silverfish beside plumbing pipe

What do Firebrats Look like?

Firebrats closely resemble silverfish, except they do not have the silvery sheen, and are grey or brown with darker markings on their bodies. They appear molted. Firebrats measure 1 to 1.5 cm in length, and are also quick movers.


Upon emerging from their eggs, both young silverfish and firebrats resemble miniature versions of full grown adults.

What do Silverfish and Firebrats Eat?

Silverfish and firebrats primarily feed on dead insects and materials high in protein, sugar, or starch, including cereals, flour, dog food, wall paper, book bindings, cereal boxes, and other paper products containing starchy paste or glue. They leave behind irregular holes in wallpaper and books (from biting through the paper fibres to get to the paste). Silverfish can also bite tiny holes in fabrics (silk, cotton, linen and rayon). They cannot digest linen or cotton. Firebrats have a strong preference for rayon.

Do Silverfish and Firebrats Bite or Cause Damage?

While they do have chewing mouthparts, these are used to scrape surfaces, or bite off small particles. Silverfish and Firebrats are harmless to humans and pets, and do not bite. When disturbed, both insects are known to swiftly take off to hide in cracks and crevices.

These insects are a nuisance by their ugly appearance, and ability to damage or stain materials, fabrics, clothing, wallpaper, food in pantries, papers, cardboard, photos and books. Silverfish leave yellow staining, and tiny holes in materials they bite.

More About Silverfish

  • They can be found almost anywhere in a home or business.
  • They prefer dark, damp, cool locations, and commonly inhabit basements, attics, kitchens, bathrooms, laundry rooms, garages and sheds.  
  • Given the right humid conditions, Silverfish populations can grow quickly, as nymphs develop faster in humid environments.
  • The most common places they are discovered by humans are around or in bathtubs, sinks, plumbing fixtures, damp paper or clothing piles, or stored cardboard boxes in basements, sheds or garages.

The life cycle of silverfish takes three to four months (egg to nymph to adult).  Female silverfish can produce eggs year-round, and several generations of silverfish are possible in a year. Females are capable of producing 1 to 3 eggs per day, and often deposit them inside small cracks or crevices. Silverfish go through many molts (up to 50) as they develop into mature adults, and they continue to molt throughout their lives. Silverfish average lifespan is 2-8 years.

More About Firebrats

  • Firebrats prefer dark environments with warm high temperatures and humidity.
  • They favour attics and areas around ovens, dryers, water heaters, steam pipes and furnaces.
  • They are drawn to moisture, and are often discovered in bathtubs, laundry tubs and sinks.

Female firebrats begin laying batches of 50 eggs between 1.5 and 4.5 months depending on their habitat. They are capable of laying as many as 6,000 eggs in their lifetime. Nymphs typically hatch 12-13 days, and can reach maturity within 2 to 4 months time. Several generations of firebrats are possible each year. Firebrats average lifespan is 3-5 years, and like silverfish, they molt throughout their lives.


Getting rid of silverfish and getting rid of firebrats can be successful through cleaning, sanitation, controlling humidity and preventative maintenance and upkeep.

Here are some tips to help you deal with silverfish and firebrats in your home or business:

  • Routinely vacuum, focusing on baseboards, open vents, and cracks and crevices to remove food particles and possible eggs.
  • Routinely clean and disinfect:
    • Interiors of cupboards, drawers, and pantries
    • Countertops, sinks, bathtubs and laundry tubs.
    • Under sinks and around the base of tubs.
    • Areas around appliances and machinery - do not forget to get behind them.
    • Baseboards, especially in kitchens, bathrooms, laundry rooms, basements, and any other lower level rooms.
  • Regularly inspect faucets and pipes for leaks, and repair them timely.
    • For pipes with too much moisture, insulate or wrap them.
  • Manage indoor temperature and humidity levels through dehumidifiers, air conditioning units, and fans.
  • Install ventilation in bathrooms and other high humidity area, and maintain them so that they are in good working condition.
  • Seal holes and cracks around windows, doors, and baseboards with high quality caulking.


If you have an silverfish infestation or a firebrats infestation in your home or business, contact Environmental Pest Control for a quote, and to book your service.

Call 1 (800) 263-5055

Our Professional Team is Happy to Help!