Identification
Silverfish have no wings, and range from silver to brown in color. They are flat, scaly, elongated insects with two long antennae and three "tails" that come out their backside.
Types
A firebrat is very similar insect, but usually darker than silverfish. Both firebrats and silverfish like humidity, but firebrats especially like heat, and are often found near ovens and other hot places.
Life Cycle
A female silverfish constantly lays eggs, usually in cracks. These eggs typically hatch in three to four weeks. The young silverfish take about four to six weeks to become adults, although they will molt all their lives.
Lifespan
Although there is some disagreement about their lifespan, a silverfish lives two years, though some can live up to three or four years. The Field Guide to Texas Insects website claims they can live up to eight years.
Special Note
Not only do silverfish live a long time, but they can survive over a year without any food at all.