The firebrat (Thermobia domestica) is a small insect (typically 1–1.5 cm) in the order Zygentoma.

[2] They are commonly found indoors near heat sources such as furnaces and boilers.

They feed on a wide variety of carbohydrates and starches that are also protein sources such as dog food, flour and book bindings.

[3] At 1.5 to 4.5 months of age the female firebrat begins laying eggs if the temperature is right (32–41 °C or 90–106 °F).

The sequential changes occurring during the prophase I stage of meiosis in T. domestica ovaries have been described in detail.