Why can firebrats damage stored foods and fabrics?

The firebrat (Thermobia domestica) is a wingless insect belonging to the order Zygentoma, a group often categorized among apterygotes.12

Firebrats are capable of damaging stored foods, books, and fabrics because they feed on starches. Their dietary habits are similar to those of the silverfish, which also consumes starchy materials such as paste, bookbindings, and wallpaper. Because these insects thrive in warm indoor environments—often near heat sources like furnaces or fireplaces—they frequently come into contact with household items containing the starches they require for sustenance.134