“Silverfish” is the popular name given to lepisma saccharina because it has a cigar-shaped body covered with silvery scales. It is, in fact, an insect with six feet but no wings. It has two long antennae on its head and at the other end of its body are three narrowed appendages (a central filament located between two cerci). Our homes can also be host to the firebrat; it resembles the silverfish, but its marbled body is more beige and brown. Other species of silverfish and firebrats live indoors, although most take advantage of warm and humid climates to live outdoors in birds’ nests or hidden under rocks and bark.
These insects feed on starch and are therefore attracted by glossy pages, the gum used to bind books, wallpaper, and some types of clothing or curtains (cotton, linen, silk, rayon). They also feed on cellulose that they find in cracks of houses, as well as grain and dried meat. On the other hand, silverfish can fast for several months. They are active at night, run away from light quickly, and can even jump.
Insects develop in different ways. Silverfish do not undergo true metamorphosis. As a result, there is no drastic change in the insect’s appearance, unlike that which occurs in caterpillars that change into butterflies. Silverfish start out life as an egg (inserted into a crack), then become larvae similar to the adult but smaller, and incapable of reproducing before reaching the adult stage. Like all insects, these major stages are interrupted by several molts. During such periods, the larva stops feeding and loses its outer shell which has become too small. The silverfish is exceptional among insects because it undergoes a number of molts even after becoming an adult.
Places where they can be found in the home
This insect looks for dark, humid and cool places where it can hide. It is therefore usually found in bathrooms, basements or kitchens. It can be found under sinks, near bookcases, closets, plinths, door or window frames, or inside walls. Once it discovers its source of food, it does not venture very far away. You cannot detect its presence quickly unless you surprise it at night or find one trapped in the bathtub or some other structure with slippery walls that will not allow it to escape. Silverfish can leave yellowish spots on clothing. To find out if they are present in your home, place some sticky traps normally used to detect cockroaches, or spread a mixture of water and flour on a piece of cardboard to attract them. The damage that this insect inflicts on paper and cardboard can be recognized by the presence of tiny irregular holes similar to lace.
- Be careful when bringing home boxes that have been stored in a humid basement.
- Repair any leaky faucets or pipes and try to minimize condensation.
- Monitor humidity levels in the home regularly.
- Do not leave dead leaves around the house.
- Plug up small openings to prevent the insect from passing from one apartment to another.
- Seal up openings that would provide shelter or a hiding place for eggs.
- Vacuum the bathroom regularly, especially if cosmetic powders are used.
Silverfish do not usually cause major damage but their presence does indicate that the humidity is too high. You should remedy the situation before other undesirable insects looking for just such conditions set up housekeeping in your home. To lower the humidity in a room or a new home, ventilate it or install a dehumidifier. More rarely, the discovery of this insect indicates that its source of food needs to be put out of reach. Keeping lights on in rooms will discourage it.
The vacuum can be used to capture specimens. A glass jar covered outside with masking tape can be used to capture any silverfish that climb in. You can then add soapy water to kill them. You can also trap them in a box they can access via a piece of cardboard serving as a ramp. The inside should be covered with Vaseline to prevent them from leaving. Diatomaceous earth can be sprinkled around regularly to cause the silverfish to scratch their bodies and die by dehydration. Some authors suggest raising the temperature temporarily (to over 44 degrees Celsius) in places in the home that can withstand such a treatment.
Insecticide is not the preferred method of control to use when you see an insect in the home. You should look for information about the insect you found and try to deprive it of the things it is looking for.
Another interesting fact
Some species of silverfish live outdoors in anthills or termite mounds where they steal food. The scales on their bodies are hard to hold onto and help protect them against ants.