Bug FAQFirebrat
Thermobia domestica · Order: Zygentoma · Family: Lepismatidae
Also called: Fire brat
Source: Wikipedia
Firebrats are small insects about 1 to 1.5 cm long and look like silverfish but prefer warm spots in homes.
Source: Wikipedia
Size
An adult firebrat measures roughly 1 to 1.5 cm in length.
Source: Wikipedia
Is it a pest in the house?
They are commonly seen near indoor heat sources like furnaces and boilers. Although they do not cause major damage, they can contaminate food, stain clothing and damage paper goods.
Source: Wikipedia
Does it bite or sting?
Firebrats are essentially harmless and do not bite or sting.
Source: Wikipedia
Where it lives
Indoors they are found near furnaces, boilers and other heat sources; outdoors they hide under rocks and plant litter.
Source: Wikipedia
What it eats
They eat a variety of carbohydrates and starches such as flour, dog food and book bindings. They also practice cannibalism, feeding on eggs, shed skins and dead firebrats.
Source: Wikipedia
Life cycle
Females start laying eggs when they are 1.5 to 4.5 months old if the temperature is between 32 °C and 41 °C.
Source: Wikipedia
When you see it
Egg-laying begins at 1.5 to 4.5 months of age under suitable warm conditions.
Source: Wikipedia
Where it comes from
Firebrats occur in most regions of the world.
Source: Wikipedia
Lookalikes
They look similar to silverfish.
Source: Wikipedia
Where it is found in the US
Recorded in 38 of 51 states and DC. Most records: California, Arizona, Texas, Nevada, New York, Alaska, Washington, Colorado.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: introduced in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
Where in my house are firebrats found?
They are usually found near heat sources such as furnaces, boilers and other warm spots.
Source: Wikipedia
What do firebrats eat?
They feed on carbohydrates and starches like flour, dog food and book bindings, and may also eat other firebrats' eggs and dead bodies.
Source: Wikipedia
How long do firebrats live?
A firebrat can live about 3 to 5 years and may lay up to 6000 eggs during its lifetime.
Source: Wikipedia
Same family (Lepismatidae)
CtenolepismaCtenolepismaCan damage your home
Long-tailed SilverfishCtenolepisma longicaudatumCan damage your home
Common SilverfishLepisma saccharinumCan damage your home
Four-lined SilverfishCtenolepisma lineatumNuisance, not dangerous
Ctenolepisma ciliatumCtenolepisma ciliatum
Mirolepisma deserticolaMirolepisma deserticolaSources
- Wikipedia: https://en.wikipedia.org/wiki/Firebrat
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.