Silverfish are small primitive, nocturnal wingless insects, having a fish-like appearance and overlapping scales covers their flat body, which is tapered at both ends. They are found in dark, damp, warm places throughout homes. Another area to check for silverfish is wood mulch ground covers outdoors near the house. Silverfish can be delivered with mulch and breed within the mulch where heat and moisture are generated by the natural composting process. They prefer starchy foods such as cereals, wallpaper pastes and bookbindings but in large populations they may do damage to paper, cotton and linen fabrics. They will also eat breadcrumbs and other human food. Silverfish can feed on mold or fungi or survive without any food for long periods of time. While many insects have a four-stage life cycle (complete metamorphosis), these undergo only a three-stage life cycle called gradual metamorphosis. Once they hatch from the egg form, all stages appear similar in appearance, except for size. Silverfish may lay eggs at any time during the year, and take 19-43 days to hatch. The life cycle from silverfish egg to adult is three to four months.