Silverfish have a long slender body, flattened and normally 13-25mm, giving them a fish like appearance. They completely lack wings and have two antennae which move side to side like a fish. Silverfish have chewing mouthparts, cannot climb smooth surfaces and are nocturnal. They can typically live for two to four years. They do prefer warmer temperatures and will die in heat over 40 degrees.

When indoors they can be found in roof cavities, wall cavities, subfloors, and in cupboards. They will eat foods like rolled oats, sugar, synthetic fibres. They can go for long periods of time without food, and signs of feeding are not obvious. They are fast and agile insects and this sometimes contributes to their downfall, as they often become trapped in bathtubs.