The **Firebrat** (*Thermobia domestica*) is a small, wingless insect closely related to the Silverfish, belonging to an ancient order of insects. Unlike the Silverfish which prefers cool, damp environments, the Firebrat requires and thrives in high heat and high humidity, commonly infesting areas near ovens, furnaces, fireplaces, and hot water pipes. They are considered household and occasional stored product pests, primarily causing damage by feeding on starchy materials and glues.
Taxonomy and Classification
Firebrats belong to the order Zygentoma (formerly Thysanura). They undergo simple metamorphosis (egg, nymph, adult). They are nocturnal and notoriously long-lived, potentially surviving for up to six years under ideal conditions. Their high-temperature requirement is unusual for a common household pest.
Physical Description
The adult Firebrat is about $1/2$ inch long, tear-drop shaped, and lacks wings.
- **Coloration:** Mottled gray or brownish, often appearing speckled, which distinguishes it from the uniformly silvery Silverfish.
- **Appendages:** Possesses long, multi-segmented antennae and three long, tail-like appendages (two cerci and one medial filament) at the rear.
- **Movement:** They are fast runners and immediately seek cover when disturbed.
Distribution and Habitat
The Firebrat is cosmopolitan and distributed worldwide. Its habitat is characterized by temperatures between $90^{\circ}\text{F}$ and $108^{\circ}\text{F}$ ($32^{\circ}\text{C}$ and $42^{\circ}\text{C}$). Typical indoor locations include boiler rooms, furnace areas, wall voids near heating ducts, and behind pipes in commercial facilities (bakeries, laundries). They are common in attics exposed to high summer temperatures.
Behavior and Damage
Firebrats are general scavengers that feed primarily on carbohydrates, cellulose, and proteins.
- **Diet:** They consume anything containing starch or polysaccharide glue, including book bindings, paper, wallpaper paste, linen, cotton, rayon fabrics, dried foods, and stored flour.
- **Damage:** Feeding damage appears as irregular holes or scrape marks on paper and fabrics. In large populations, they can cause significant damage to archived documents and library materials.
- **Reproduction:** Females lay eggs in secluded cracks and crevices, and development from egg to adult is prolonged, often taking several months to a year.
Management and Prevention
Control focuses on eliminating their required environment and reducing food sources.
- **Environmental Modification:** Reducing the ambient temperature and humidity in the infested area is the most effective long-term solution.
- **Sanitation:** Eliminating or sealing all starchy food sources (flour, cereals) and removing or sealing paper products. Vacuuming frequently helps remove eggs and food debris.
- **Sealing Entry Points:** Sealing cracks and crevices in the walls, floors, and baseboards to reduce harborage sites.
- **Chemical Control:** Applying insecticidal dusts (such as boric acid or diatomaceous earth) into wall voids and other hidden harborage sites where the insects live and travel is highly effective. Residual perimeter sprays can also be used in areas where they are sighted.
Conservation and Research
Firebrats are managed as minor structural and nuisance pests. Research focuses on their physiological adaptations to extreme heat and their use as laboratory models for basic insect biology studies.