The silverfish and the firebrat are present-day members of a very old and primitive insect group. The adults are wingless, about 1/2 inch (10 to 12mm) long, and have three long bristles at the tail end of the body.

The silverfish shown at right is covered with shiny grayish white scales. It prefers damp places in basements, bathrooms, and porches.

The firebrat is mottled with brownish and blackish scales and prefers much higher temperatures, breeding rapidly at temperatures around 100 degrees F. They are common around furnaces, trash incinerators, fireplaces, and in insulation around hot water or heat pipes.

Both silverfish and firebrats feed on vegetable matter with a high protein, starch, or sugar content; they are active at night and hide during the day. They can cause damage to book bindings, starched fabrics, wallpaper paste, and stocks of paper on which paste or glue is present.

New houses may become infested with them before the plaster and woodwork are thoroughly dry. Basement food incinerators also attract them and provide a constant source of food, often making their control more difficult. They take from 3 to 24 months to mature and may live as long as three years.

Control requires preventative measures such as strict sanitation, sealing cracks and crevices, removing food and moisture, etc., in conjunction with insecticide treatments. If you choose to use an insecticide, a ready-to-use formulation of propoxur or chlorphyrifos is suggested. 

Courtesy MSU Extension