Silverfish (and their cousins, the firebrats) may be relatively harmless, but they sure are ugly. The common silverfish – or the lepisma saccharina – is a wingless insect that wriggles around when it moves. Their name is representative of their silvery color and their strong resemblance to fish. Their scientific name comes from the fact that they rely mostly on carbohydrates to survive, which they obtain from starches and natural sugars.
Silverfish find their way into homes through cracks and gaps or get carried in on boxes or bags from other infested locations. Once they find a place they deem fit to live in, they will likely stay there until you get rid of them.
Signs of a Silverfish Infestation
Silverfish can live in any environment, but they prefer warm and damp areas. Five main signs could indicate their presence and signify that you have a problem you need to get rid of.
Seeing Live Silverfish
This may seem obvious to you, but unless you can accurately identify one, you may realize the problem. Silverfish are small, up to 1 inch in length, and have no wings. They have flexible, slippery scales on their bodies and range in color between brown-gray to bluish-silver. They are shaped like a teardrop.
Silverfish move in a way that makes them look like they’re swimming by wriggling back and forth. These creatures are nocturnal so you may not see them often, but that doesn’t mean they’re not hanging around. Seeing one live doesn’t necessarily mean you have an infestation, but is enough of a cause for further inspection.
Silverfish droppings are fairly unique, and can sometimes be used to identify their presence. Their droppings look like small, black peppercorns and can be found in places silverfish like to go often, such as kitchens, basements, garages, etc. Without carefully examining them, these droppings can be easily missed and brushed aside under the assumption that they are general dust or debris.
Silverfish shed skin throughout their life. These outer shells are fragile and barely noticeable, but if examined properly, they can be another important clue to an infestation.
If not the skins, you might see yellow-ish dust on surfaces where the shedding process has taken place. You might also see yellow stains in books, papers, and cardboard boxes, indicating that silverfish have been there.
This might be the easiest and most common way of realizing that there is a silverfish infestation in your home. The damage silverfish cause can be extensive, including small holes in clothes, wallpaper, cereal boxes, cardboard and other kinds of fabric material. Silverfish love carbohydrates and feed on it wherever they can find it. Unfortunately, this could happen to be among your belongings.
If you find yourself dealing with an uninvited silverfish infestation, you can try getting rid of it in a variety of ways. You can trap them, repel them, kill them with insecticides, or at the very least, make your home a less hospitable place for them to live.
How to Trap Silverfish
For any kind of silverfish trap, you have to first identify where they are hiding. These pests are nocturnal, so you might not notice them during the day. But what they leave behind after their nighttime adventures can surely alert you of their presence. Look for them in dark, damp areas with high levels of humidity and check for their droppings.
Once you’ve managed to locate where they live in your home, you can start with the traps.
Get a quart-sized mason jar or any other kind of glass container and wrap the outside with masking tape. In the bottom of the jar, place a piece of bread, and keep the jar where you suspect the silverfish to be.
Since silverfish love starchy carbohydrates, like glue, paper, flour and rolled oats, you can use newspapers to trap and get them out of your house. Roll up a newspaper, place elastic bands over the ends and moisten it. Before you go to bed, put this newspaper where you find the remains of silverfish activity.
In the morning, you will likely find that the silverfish have eaten their way through the newspaper. Without unrolling it, throw the newspaper out or burn it. Repeat this process every day until you see no more signs of silverfish.
If you don’t have any newspaper or if you don’t like the idea of silverfish touching you hardware, you can trap the pests with store-bought silverfish traps. You don’t need to specifically buy silverfish traps; any sticky traps you can find at your local store will work.
You can also opt for a homemade roach killer trap or smaller versions and set them around your house. These usually work best when the bugs are baited with bread and other starch sources.
How to Kill Silverfish
If your home has become infested, there are several ways you can deal with them. Some of these techniques involve using non-toxic ingredients so that the silverfish can die over time instead of in one go, while others use commercial chemicals to get rid of them at once.
A great way to address pest problems, including silverfish, is to use food-grade diatomaceous earth. This powdery substance is comprised of a ground-up fossilized material with sharp edges that slice through the exoskeletons of insects and the powder then dries them out, causing them to die of dehydration.
To use diatomaceous earth to kill silverfish, lightly sprinkle the powder in your cabinets, along baseboards and anywhere else you think they might be lurking before you sleep at night. In the morning you can vacuum up the powder and the dead insects. Since this is a naturally occurring organic material, it is non-toxic and safe to use around children and pets.
This is another natural substance that can kill both silverfish and their eggs. You can use this easily by sprinkling it along the baseboards of your home, under bathtubs, or any area where you notice signs of an infestation. When applying the boric acid, you want to be very careful that you don’t inhale the product since it can be toxic to your lungs. You also want to avoid using it in places where children or pets can get into it.
Pyrethrin insecticide is a natural derivative of the pyrethrum daisy. It contains toxins that kill insects upon contact. Although it is a naturally occurring organic substance, pesticides containing Pyrethrin are still very toxic to mammals, so you will have to be very careful if using it in a house with children and pets.
Similar to boric acid and diatomaceous earth, you want to spray the insecticide along baseboards and in cracks, as well as anywhere you might have found evidence of silverfish. The substance is extremely toxic, so it is advised not to use it in kitchen cabinets or near food sources.
Propoxur, like Pyrethrin, is effective against a variety of insects. It is available in powder or liquid form, and can kill adult silverfish in one go, but does not help in eradicating their eggs.
Thus, propoxur is not a one-time solution and requires you to use it over an extended period of time, especially when dealing with severe infestations. Since propoxur is a toxic chemical, make sure to read the instructions very carefully and take the required precautions when handling it.
One of the cheapest and most effective remedies for controlling silverfish is baking soda. To kill silverfish with baking soda, all you have to do is add some to a bowl with one cup of water and some honey. Stir the ingredients thoroughly until they form a paste.
You can apply this paste to several small pieces of cardboard and place them in areas where the silverfish are likely to lurk. The insects consume the mixture and the baking soda works to dehydrate them. This method works great, especially for hard to reach places such as bookshelves.
How to Repel Silverfish
If you’re looking for a non-toxic method to repel silverfish, you want to start with the ingredients you already have in your kitchen cabinet. There are several inexpensive products that are extremely useful in controlling silverfish. All of these methods are also non-toxic so they are safe to use around children and pets.
Cedarwood is an excellent silverfish repellent. Silverfish and spiders absolutely hate the smell of cedar, so you can keep them away by sprinkling some of the product in areas where they may live. The shavings can cause quite a mess. So you might want to limit their use to outside your home or at least in the basement; areas where you don’t mind having wood shavings lying around. You should vacuum and replace these with fresh shavings every week.
You can also use dilute cedar essential oil with water, and apply it with a spray to the cracks and crevices of your house. The smell coming from the oil is very unpleasant for the silverfish and also to other common household insects. By spraying this around the house regularly, you can create a barrier that will keep them from re-entering your home.
Strong Smelling Spices
Spices and herbs with strong smells are found to be very useful in repelling silverfish. You can create little sachets with generous helpings of spices like bay leaves, cloves, dried rosemary or cinnamon sticks and place these around the house or kitchen. With these intense smells, you can avoid these pests getting into your food.
Lavender or Citrus Spray
Just like with gnats and some other insects, citrus and lavender have strong scents that are used to repel silverfish and are safe to use around the house. Take some lavender or citrus essential oil and dilute with several drops of water. Pour this solution into a spray bottle and use it around the house in areas you want to keep silverfish out of. These sprays are usually best in drawers, closets, and other bedroom areas.
How to Prevent Silverfish
Of course, if you don’t have any silverfish in your house yet, or perhaps you got rid of an infestation and want to prevent another one, you can take some steps to prevent these pesky creatures from entering your house in the first place.
Silverfish are picky about their living conditions, so you can take steps to make your home an unwelcoming place for them.
Dehumidify your Home
Silverfish love damp places, so a good way of keeping them out is to reduce the humidity levels inside your house. You can buy a dehumidifier from your local store for this purpose, or if you want to save money, just keep the fans or air conditioner on. This will lower humidity enough to keep these insects moving on the search for more moist conditions.
Seal Up Food
You already know silverfish love starch, so to stop them from invading your pantry, you can seal up your dry food like pasta, rice, cereal, flour, sugar and even pet food in airtight containers. By keeping these starchy foods sealed, you can stop silverfish from coming over uninvited on the search for dinner.
Seal Up Cracks and Crevices
Cracks and openings in your house can not only be a route for silverfish to enter your house, but can also become great places for them to lay eggs. If your house is full of dark, damp cracks and crevices, you might want to fill these up and keep the silverfish out. Applying caulk to these cracks and along the baseboards can be helpful, and is important for the basement, kitchen, bathrooms and laundry rooms where you can expect it to be more humid than other areas of the house.
Fix Leaky Pipes
If you have leaky pipes in your house, you are practically inviting silverfish over to stay. Leaky pipes, when left untreated, can provide favorable conditions for these pests, so you would want to go over your house and repair these.
Remove Food Sources
Try to keep your floors clear of the food these insects like to eat. Don’t leave piles of books on the floor, or your dirty laundry sit for too long. Make sure cardboard boxes are kept on shelves and not the floor, and replace old wallpaper with a newer one, or with paint.
Not only is vacuuming good for keeping the food sources under control but this way, you also get to suck eggs out of the carpet and baseboards. To keep silverfish out of your house, vacuum the floors once a week. You can also dry out your carpets, sprinkling baking soda over the surface and leave for several hours before you vacuum it up. This dries out the eggs so you can suck them up.
Silverfish love hiding and feasting on old books, newspapers, etc. If you like to hold onto everything you’ve ever used in your life, now might be a good time to change this habit. Start getting rid of items you haven’t looked at in a while because you might just be providing silverfish with an all you can eat buffet. If there are things you just can’t get rid of, store them in air-tight bins.
While silverfish are creepy and ugly, they are not venomous and don’t bite. Even so, it is best to get rid of them as soon as an infestation has been identified to keep them from damaging your home and possessions.