Silverfish belong to a very primitive group of soft wingless insects, evolving on earth even before the cockroach. They have a distinctive carrot-like form, long and slender, broader at the front end and gradually tapering to the rear. Their name is derived from silver, flattened, hair-like scales scattered over the body and the Greek: thysan, a fringe, and ura, the tail. The fringe comes from the "tail" is made up of three long posterior filaments. The young look very similar to the adults only they are smaller.

All silverfish are vegetable eaters, some are subterranean or live in caves, and others are found in ant and termite nests. One species is a major cosmopolitan pests, the common silverfish (Lepisma saccharina). This species occurs in domestic situations, feed on starchy materials, such as books, boxes and paper towels and may be able to withstand considerable drying (they prefer moist habitats when possible). They can also survive long periods without food.

Uniformly silver to slate or pearl gray, ½ inch in length, silverfish are a common pest in homes, libraries and museums where they eat paper, fabrics, and get into cereals. They have mandibles that can remove the sizing of paper in books, and magazines, damaging etchings and prints. They nibble on book bindings and feed on the glue and paste in the binding. This insect prefers cool, damp situations; their preferred temperature range is 72 to 80 degrees F with 72 to 95% relative humidity. The common silverfish can live for as long as two years and may molt up to 50 times during this period. There are other species of silverfish that may also be present and their identification, biology and control are similar.

If you see silverfish running over the floor, you can be sure there are more specimens lurking behind the walls, in voids of shelving and under baseboards. Their eggs are very small, often laid in cracks and crevices and are carried into buildings along with cardboard boxes and other shipping containers. A single female may lay less than 100 eggs during her lifetime of 2 to 3 years. These insects are primarily nocturnal and will quickly retreat into hiding when lights are turned on.