Silverfish are primitive (i.e., older than cockroaches), wingless insects that are ½-inch long when fully grown. They are covered with silvery scales and are flattened and somewhat “carrot” shaped. Three long, slender “antennae-like” appendages project from the end of the abdomen, giving them the name ”bristle tails.”
The female lays one to three eggs per day in crevices or under objects. The female molts after laying a batch eggs and sheds her skin as many as 50 times after becoming an adult. The eggs hatch in about 43 days at 72-90°F and at least 50-75% relative humidity. They young silverfish look exactly like the adults, except smaller, and feed on the same foods. Under ideal conditions, they molt every two to three weeks becoming adults in three to four months. However, under poor conditions, this might require two to three years. These insects are very long-lived, commonly living at least three years. The silverfish are unlike most other insects in that they continue to molt after they become adults.
Silverfish are tropical insects that easily adapt to the structural environment. They live in warm (71-90°), moist locations in the structures; hide during the day; and rest in tight cracks and crevices. They roam great distances looking for food, but once a food source is located, they remain close until the supply is exhausted. They can be found throughout a structure from the basement to individual floors to attics to shingles on the roof. Outdoors, they can be found in mulch, and under siding and roof shingles, particularly cedar shakes.