Silverfish: They are Silver, but They're Not Fish
Silverfish and firebrats are about a half-inch long, wingless, flat insects with two long, slender antennae on the front and three long, slender "bristles" at the rear of a tapered, carrot-shaped body. As a kid those three bristles held at right angles always seemed to add to my presumption that there were perhaps an alien listening device and not insects at all. Most silverfish and firebrats are covered with scales (similar to those on butterfly wings) that have a silvery sheen in the case of silverfish.