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, wallpaper, 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. Learn more about how to get rid of silverfish and firebrats.

If you have a silverfish infestation or firebrat infestation and need professional help, you can count on Environmental Pest Control. We are experts in silverfish pest control and firebrat pest control.

Call 1 (800) 263-5055

Our Professional Team is Happy to Help!