Both firebrats and silverfish are omnivorous and in our latitudes they are both synanthrope. The firebrat is free-living in the tropics and needs very high temperatures in order to survive. Firebrat eggs do not hatch at temperatures below 24.5 °C. Silverfish are free-living in Southern Europe and multiplies at temperatures above 15 °C.
The firebrat lives in houses in places where the temperatures are up to 35-39 °C. The relation between silverfish and people is, however, more peripheral. Silverfish live inside houses and in the summer even outside the houses.