The silverfish and firebrats that we find indoors belong to two species that are similar in shape, but not in colour.
Common silverfish (Lepisma saccharina) are wingless and have a flattened, carrot-shaped body. They have two long antennae on the head and three tail-like appendages at the tip of the abdomen. These insects are covered with metallic grey scales that give them their silvery colour.
Firebrats (Thermobia domestica) can be distinguished by their brownish beige colouring and light and dark markings that give them a mottled appearance.