Silverfish (Lepisma saccharinum) are common household pests that prefer high humidity and darkness. These small, teardrop-shaped insects are secretive, often going unnoticed until their populations are well-established. Homeowners sometimes mistake unexplained nighttime noises for silverfish activity. Identifying the exact source of faint sounds is crucial for correct pest identification.
Do Silverfish Produce Audible Sound?
The definitive answer is that silverfish do not produce sounds audible to the human ear for communication or as a byproduct of their movement. Unlike insects such as crickets or grasshoppers, silverfish lack the specialized biological structures, such as stridulatory organs, necessary to generate noise. Any sound resulting from a silverfish would be an extremely faint rustling, caused only by the friction of their bodies against paper or other materials. This minimal sound is far below the typical ambient noise level of a house and is not a reliable indicator of their presence.
Alternative Sources of Household Noise
Since the noise you hear is not a silverfish, it is likely the activity of other common house invaders or structural dynamics.
Rodents
Rodents like mice or rats create light, rapid pattering sounds as they scurry through wall voids. These sounds are often accompanied by scratching from their claws or a crunching sound from gnawing on wires and wood. These noises are typically heard late at night when rodents are most active.
Wood-Destroying Insects
Wood-destroying insects produce fainter, yet distinct, noises. Termites sometimes create a faint clicking or tapping sound, particularly when soldier termites bang their heads against tunnel walls as a warning signal. Carpenter ants, which hollow out wood for nesting, may produce a sound described as soft rustling or the crinkling of cellophane as they excavate wood fibers.
Structural Dynamics
Structural noises can also mimic pest activity. A sharp ticking or creaking sound is often the result of copper or plastic plumbing pipes expanding and contracting against wooden supports when hot water is run.
Confirming a Silverfish Infestation
Because sound is an ineffective way to detect silverfish, identification relies entirely on visual and physical evidence. Look for tiny, black, pepper-like specks in dark, damp areas, as these are their droppings. Silverfish also shed their exoskeletons, leaving behind translucent, scale-like skin castings. The most telling sign is the damage they inflict on starches, cellulose, and glues. Check books, wallpaper, cardboard, and stored fabrics for irregular holes, frayed edges, or surface etchings, or look for small, yellowish stains on paper or cloth.