Why Are There Silverfish All Over My House?

If you’ve ever had to clear out shelves or do house cleaning in an apartment, you’ve probably come across three types of bugs: ants, roaches and silverfish. The last one is probably the least damaging of the three bugs, but still considered to be annoying.

However, unlike ants and roaches, silverfish can be easily remedied and removed with very little chemical effort.

Silverfish Definition

These bugs were given the name due to their silver skin colour and their mode of movement that looks like a fish out of water. Silverfish are insects with antennae. The University of Arkansas Department of Agriculture says, "It is scaly, has a silvery sheen, and it is about half an inch long at maturity. It is active at night and hides during the day." They are frequently found in moist, dark areas and they run from bright light. The insects are long-living, as much as two to eight years depending on conditions, and they can survive for up to one year without a food source.

What Silverfish Eat

Unfortunately for dry food lovers and book collectors, Silverfish go after both material that has starch and polysaccharides. This makes books, paper, anything with sucrose or dextrose in it and basic body dander fair game for food. Silverfish even eat hair. It’s not surprising that they find homes to be so compatible with their diet given their food preferences.

Damage Level

The damage silverfish cause is minimal compare to that of ants, roaches or rodents. However, for books, it can be very damaging. Book glue and binding can be particularly susceptible to these creatures due to their dietary interests. Clothes that are pressed with starch from the cleaners are susceptible as well. Fortunately, silverfish are not disease carriers. Aside from books, at most, they contaminate food in a pantry causing it to be thrown away by the owner when found.

How Silverfish Get Introduced

Silverfish can get into a home primarily one of two ways: either they travel in through the foundation or they are carried in via a cardboard box or similar item. Once inside, the insects begin to move around in their new environment looking for moist areas combined with food sources. They usually zero in on the kitchen and pantry but can also be found frequently in bookcases. Homes with leaky faucets or tub caulking will also create enough moisture to establish breeding grounds for silverfish. The University of Minnesota states, "They are often associated with basements, closets, bookcases and storage areas."


When a silverfish is seen, it is more often than not near its food source. Look around the immediate area to identify potential food sources and moisture zones. Drying these areas out and removing the starch and sugar sources will very likely drive away any remaining population of the bugs. Repairing leaky pipes or bad caulking seams, ventilating damp areas and sealing off tile floors to the foundation helps eradicate them. Heat will quickly dry out a high-humidity area and will cause the silverfish to run away as well.