Silverfish are small insects that can infest a home. Although they are not dangerous, they can damage property and trigger allergies. A person can try several natural and chemical methods to get rid of them before contacting a professional pest control service.
Silverfish are a type of wingless insect that lives worldwide, including throughout the United States.
They tend to occupy gardens in places with high moisture levels, such as under piles of leaves or wood or in gutters.
Silverfish can find their way into a person’s home through gaps, cracks, and holes in the building’s exterior, and they can cause damage to both the building and people’s possessions.
This article explains what silverfish are and how to get rid of them.
Silverfish get their name from the color of their scales, which are silver or metallic brown.
Their bodies are long — typically 12–19 millimeters — and fish-like, and they have six legs and two antennae.
Silverfish are also called bristletails because they have three long bristles on the end of their body.
People most often find them in moist or humid places, such as bathrooms, basements, laundry rooms, or attics, but they can be present anywhere in the home. They are nocturnal, which means that they are most active at night.
Silverfish feed on the sugar and starch in a range of household items, such as books, photographs, documents, and wallpaper.
Soap, hair, dandruff, and dust can also be food sources for silverfish, along with glue, clothing, silk, cotton, and linen.
These insects can also eat dried beef products and even other silverfish. Other food products that they can eat include:
Silverfish are shy insects and will hide from humans. They cannot fly or bite, but they can run very quickly.
They can also breed very rapidly, which means that infestations can quickly escalate.
According to The Wildlife Trusts in the United Kingdom, people may see silverfish in the home all year round.
Silverfish can cause damage to homes and property, and they can sometimes trigger a person’s allergies.
A 2015 study into different types of indoor allergens noted that a person who has an allergy to silverfish might experience respiratory symptoms.
The scales that silverfish shed contain a protein called tropomyosin, which can combine with other allergens and sometimes cause allergic reactions. A person may also be allergic to silverfish droppings.
Silverfish can also contaminate food products, such as flour and meat.
According to the National Pest Management Association (NPMA), the signs of a silverfish infestation include:
- feeding marks, such as holes, notches, or etches, on a surface
- yellow stains or scales in the affected area
- feces, which appear as tiny black pellets
People can use various techniques to tackle a silverfish infestation, including both chemical and natural methods.
Silverfish can be picky when it comes to eating bait, and commercial baits often do not work against silverfish.
Additionally, silverfish can survive for a very long time without eating or drinking, which means that they will not resort to eating bait because of hunger.
People should only use insecticides for large infestations, and they will not work while suitable habitats remain available to the silverfish.
Even if people remove these habitats, insecticides can take a few weeks to work.
Experts note that sprays that include the following ingredients can be effective against silverfish:
- synergized pyrethrin
In one study, commercial bait formulations that included 0.05% or 0.20% chlorfenapyr were the most effective in killing silverfish.
A person should always follow the instructions on these chemical products to ensure their safety. They should also check that they are allowed to use them in their chosen environment and in their state.
People should also not use chemicals in areas where they may contaminate food or water or where children or pets may accidentally consume them.
Some people may prefer to try natural methods of eliminating a silverfish infestation before they use chemicals. In this case, the first steps involve reducing the amount of moisture and humidity in the area in which the silverfish are living.
A person can use a dehumidifier to reduce the humidity to levels that make the area uninhabitable for silverfish.
If there are dark places for silverfish to live, clearing out these spaces will reduce the number of places they can use to shelter.
Anecdotal evidence suggests that the following natural ingredients can repel silverfish:
- cedar shavings
- cedar oil and water
Diatomaceous earth (DE) is a powder made of fossilized algae. It dehydrates silverfish if they come into contact with it and will eventually kill them.
Sprinkling DE in affected areas can be beneficial in controlling a small infestation, and it is safe for humans and pets.
Traps that use sticky tape or boric acid can be helpful for small infestations. However, boric acid is harmful to humans and pets if they ingest it.
Professional pest control
If a person discovers a silverfish infestation, and chemical baits or natural methods are ineffective in eliminating it, they can call their local licensed pest control professional.
The pest control professional will recommend an appropriate treatment.
Reducing the number of environments suitable for silverfish to live in is an easy way of preventing them from entering the home.
Removing piles of wet leaves and keeping wood off the ground and away from the home can encourage silverfish to find shelter elsewhere.
Sealing up any gaps, cracks, and holes in basements, attics, foundations, or outer walls can prevent silverfish from finding ways into the home.
Eliminating any damp areas in the home can also discourage silverfish from settling inside.
Keeping basements, attics, bathrooms, and kitchens clean and dry will help prevent them from living in these rooms.
People can also remove food sources for silverfish, such as dust and debris, by cleaning out closets and cupboards and dusting bookshelves.
To prevent silverfish from getting into food products, the NPMA recommend storing the products in glass or plastic airtight containers.
Earwigs, centipedes, and spiders are natural predators of silverfish. Letting house spiders remain in the home can keep the number of silverfish down naturally.
Silverfish do not bite humans or animals, do not carry disease, and are not poisonous.
However, they have the potential to spread germs if they come in from the outside and contaminate food.
Silverfish are insects that do not pose significant threats to humans.
Although they can trigger allergies in some people, they do not bite or spread disease.
Silverfish have a well-earned reputation for causing significant damage to buildings and possessions, so it is important to get a silverfish infestation under control quickly to minimize the damage that they cause.
People can try a range of methods to get rid of a silverfish infestation, including reducing their habitats within the home, using chemical baits, or opting for natural methods such as DE and traps.
If these attempts prove unsuccessful, professional pest control services should be able to help.