Body Structure

Silverfish and firebrats possess a flattened, elongated body covered with fine scales, long antennae and three tail-like appendages extending from the rear of the abdomen. They are wingless insects with chewing mouthparts adapted for feeding on carbohydrate-rich materials.

Life Cycle

Unlike butterflies and flies, silverfish and firebrats undergo incomplete metamorphosis. Young nymphs resemble miniature adults and gradually increase in size through a series of moults before reaching maturity.

Reproduction: Females lay eggs in cracks, crevices and other protected locations.

Growth & Lifespan: Development is gradual, and adults may live for several years under favourable conditions.

Behaviour: Both species are nocturnal, avoid light and remain hidden during the day.

Habitat: Silverfish prefer cool, humid areas, while firebrats are commonly found in warmer locations such as kitchens, roof spaces and around heat-producing appliances.

Diet: Both feed primarily on starches, cellulose, adhesives, paper, glue, cardboard, natural fabrics and food residues rich in carbohydrates.

Homes provide ideal hiding places together with a steady supply of food. Paper products, books, cardboard boxes, wallpaper paste, stored fabrics and food residues all provide suitable food sources. Moisture encourages silverfish, while consistently warm areas favour firebrats.

Although silverfish and firebrats are not known to spread disease, they can damage valuable household belongings. Their feeding may result in irregular holes, surface scraping and deterioration of books, important documents, photographs, wallpaper, natural fabrics and stored materials. Infestations often go unnoticed because these insects remain hidden and are mainly active at night.

Live Insects: Usually seen at night when lights are switched on.

Irregular Feeding Damage: Small holes or scraped surfaces on books, paper, wallpaper and fabrics.

Yellowish Stains: Fine yellow staining on paper or fabrics.

Tiny Black Droppings: Pepper-like droppings near hiding places.

Cast Skins: Shed skins left behind after moulting.

Silverfish and firebrats remain active throughout the year indoors, but unlike most household pests, their presence is governed more by humidity than by season as such.

Silverfish are unusually vulnerable to drying out — lacking the waxy, water-retaining cuticle most insects have, they can die within days if humidity drops below roughly 75%. Arunachal Pradesh’s consistently humid climate, sustained well beyond the monsoon months, means conditions favourable to silverfish survival are present for much of the year, not just during periods of heavy rain. Firebrats share a similarly high humidity requirement but additionally need warmer temperatures, which is why they’re typically found near ovens, boilers and other heat sources rather than the cooler, damp areas silverfish prefer.