What Are Firebrats and How to Get Rid of Them?

Firebrats (*Thermobia domestica*) are the close relatives of Silverfish that you find in the hottest spots of your home — around boilers, behind ovens, inside furnace rooms, near hot-water pipes, and in attics during summer. Where Silverfish prefer cool, damp areas, Firebrats thrive at 32–41°C (90–106°F) and actually avoid humidity below 75%.

Visually, Firebrats look similar to Silverfish — carrot-shaped body, three tail appendages, and scaly covering — but they are mottled gray-brown rather than silvery, and they prefer heat over moisture.

### What Firebrats Eat

Firebrats are carbohydrate feeders that damage:

• Book bindings and paper (especially wallpaper)
• Starch in clothing and textiles
• Glue and adhesive in book bindings, envelopes, and wallpaper paste
• Dead insects and other organic debris
• Rayon, silk, and linen fabrics
• Dried cereals and pet food (when accessible)

### How to Get Rid of Firebrats

Step 1: Reduce heat and humidity in harborage areas.

Firebrats require both high temperature and high humidity. Make their preferred areas less hospitable:

• Improve ventilation in furnace rooms, boiler areas, and attic spaces.
• Run a dehumidifier in affected areas — target humidity below 60%.
• Insulate hot-water pipes to reduce surface temperature and eliminate the heat gradient Firebrats follow.
• Fix any leaks contributing to moisture in warm zones.

Step 2: Remove food sources.

• Store books and papers in sealed plastic bins.
• Keep starch-based items (glue, paste, adhesives) in sealed containers.
• Clean up dead insects and organic debris regularly.
• Keep pet food in sealed containers.

Step 3: Apply diatomaceous earth.

• Sprinkle food-grade diatomaceous earth along baseboards, behind appliances, around pipe penetrations, and in attic corners.
• DE abrades the Firebrat's exoskeleton, causing lethal dehydration.
• Reapply after humidity changes or cleaning.

Step 4: Sticky traps for monitoring and capture.

• Place sticky traps near hot-water pipes, behind the oven, and in furnace rooms.
• Traps catch foraging Firebrats and serve as monitoring tools to gauge population density.

Step 5: Residual insecticide for persistent infestations.

• Apply a residual pyrethroid spray (deltamethrin or permethrin) along baseboards and around hot-water pipes in infested rooms.
• Professional application recommended for large or persistent infestations.

### Firebrats vs. Silverfish — Quick Comparison

| Feature | Firebrats | Silverfish |

|---------|-----------|------------|

| Color | Mottled gray-brown | Silvery metallic |

| Preferred temperature | 32–41°C (90–106°F) | 21–28°C (70–82°F) |

| Preferred humidity | >75% | >75% |

| Found near | Boilers, ovens, furnace rooms | Bathrooms, basements, damp areas |

| Active season | Summer + heating season | Year-round in damp homes |