Temperatures for Silverfish

Tom Lutzenberger

Silverfish appear frequently in homes, but the temperature they enjoy depends on the type of silverfish insect in particular. All versions and varieties can cause damage — typically to paper products and wood. However, the environments they prefer vary.

Understanding how each breed grows in its ideal set of conditions can help with eradication.


The firebrat is a high-temperature variety of the silverfish. This type of insect prefers areas with significant heat — as much as 90 degrees Fahrenheit or warmer. Preferring to function and live near sources of strong ambient heat (not burning), firebrats can appear near heaters and related piping and ovens, as well as the surrounding furniture or nooks adjacent to a well-used fireplace. Even hot-water pipes will trigger notice for the bugs if the plumbing runs frequently. Locale-wise, firebrats are common in the lower, warmer states such as Arizona. While they do avoid light, they migrate toward heat emanation in the dark.

Four-Lined Silverfish

This type of silverfish functions in both temperature modes. Formally known as the Ctenolepisma lineata, this variety of silverfish has a hardier body and longer legs. In terms of temperature, the four-lined silverfish can be found in either cold or hot climate. While the insect will migrate toward warmth given the option, it’s not the type of insect that simply dies in cold winter.

Traditional Silverfish

The common silverfish many see zipping from uncovered locations resembling itty-bitty silver slivers with antennae prefer damp, cool locations. Basements make ideal environments with their cool, slightly moist surfaces. Sinks and drains or bathtub bottoms will be likely locations due to the silverfish’s interest in moisture, but you may also find them near books and cardboard when the general area is damp.

Seasonal Migration

Different varieties of silverfish will migrate throughout a house, depending on the season. Those silverfish that like warmth will move up to attics in the winter, while those that prefer cool environments will move closer to moisture. The opposite movement occurs when summer arrives. While pesticides and chemicals will kill both, sometimes it’s better to use their temperature sensitivity against them by changing the internal environment enough that the silverfish just leave the house altogether.