Home Pest Control: Silverfish Identification, Prevention, and Removal Tips
Silverfish are small, wingless insects found throughout the U.S., often in residences. They are thought to be one of the oldest insects in existence. These bugs have been around for 400 million years, which is altogether 100 million years before the existence of dinosaurs. Although harmless to humans, silverfish can damage many starchy materials and items within the home. Learning how to prevent and get rid of silverfish is important information for all homeowners to know.
Silverfish infestations can be daunting because they reproduce quickly, can go for long periods without eating and come out only at night. Silverfish damage household items people don't often look at or think about, like old books stored in basements and seasonal sweaters tucked away in the garage. This means an infestation can get worse over many months before a homeowner will notice. When the infestation is discovered, it can be hard to tell if remediation efforts are working. Worst of all, many traditional pest control poisons have no effect on silverfish.
The best way to avoid a silverfish problem is through prevention. If your home becomes infested, making lifestyle changes and eliminating food sources can be helpful. It's important to act quickly and be thorough in your elimination tactics. Here's what you need to know to protect yourself from silverfish.
Table of Contents
- How to Identify Silverfish
- Where Are Silverfish Commonly Found?
- What Do Silverfish Eat?
- Additional Silverfish Facts
- Silverfish Prevention
- Silverfish Infestation
- How to Get Rid of Silverfish
- Prevention is Easier than Elimination
How to Identify Silverfish
Silverfish are slender and lithe. They have a wide head and abdomen plus a narrow, pointed back end. They're silvery gray, often shiny, and have six legs, which gives them a fragile and delicate appearance. Most people identify silverfish by their double antenna and three long appendages on the side of their bodies opposite their head. These three long appendages coming from the rear look like additional antennas.
Minus the antennas and appendages, silverfish are approximately one-half inch to one full inch in length. The antennas and tail can be nearly as long as the body itself. Altogether, some silverfish are nearly two inches long.
Silverfish are probably named for the shape and slenderness of their body, which gives them a fish-like appearance. To add to the effect, they have shiny scales covering the segments of their body.
Overall, silverfish have a flat body that they can easily hide under books and stacks of clutter. Unlike many insects, they have no wings. Their small legs can carry them very quickly, so they dash easily from one place to another. Some sources have described silverfish as tear-drop shaped. Their antennas can be very long, curved and flourished - similar in shape to a ponytail.
Where Are Silverfish Commonly Found?
Silverfish can be found in many parts of the country and in different environments. However, silverfish are most commonly found in dark and damp locations. Inside a home, silverfish are found in basements, bathrooms, attics, garages and kitchens. Damp clothing and paper attract silverfish, so they're often found in homes with a lot of clutter, starchy materials, and/or books.
Outside, they live under trees and bark, and in and around dead leaves. Moving a rock or a brick in your landscape will likely reveal silverfish. They prefer places with high humidity, because their nymphs thrive in moist locations.
Like other insects, silverfish go where their food source can be found. Sometimes they're found in unopened food packages, sometimes in bathtubs where they've fallen in and can't get out. A homeowner who sees a silverfish in one or two places in the home does not necessarily have an infestation. However, a homeowner who sees silverfish regularly likely has a problem.
What Do Silverfish Eat?
Silverfish famously eat starchy things. They also get their food from sources that are high in protein and sugar. Some common foods for silverfish include:
- Book binding
- Dead skin
- Dead insects
Silverfish can be destructive when they eat. They eat books, stacks of paper, bills, wallpaper, and so on. Many homeowners discover they have an infestation when they find holes in their clothes, or holes eaten through the paper in their books.
In fact, one of the reasons that a silverfish infestation can be so difficult to eliminate and so irritating for people is because silverfish have such a flexible diet. They can be found nearly anywhere in the house, eating food and possessions alike.
Additional Silverfish Facts
Silverfish have some interesting adaptations, possibly because the species is so ancient. The following characteristics make silverfish different from many other species of insects.
Silverfish have eyes that are sensitive to light, so they prefer to come out at night. Their antennas help them feel along the surface of wherever they're running.
Silverfish have no natural defenses against predators. Without the ability to fly, sting, bite or attack other insects, their one self defense comes from their ability to run very fast. It's said, however, that silverfish cannot grip vertical surfaces as easily, so they slow down significantly when running up a wall.
Immune to Bug Poison
Silverfish are immune to most forms of bug poison, which makes them hard to eliminate from an infested home. To make matters worse, females can lay up to 20 eggs per day. This can make silverfish an incredibly difficult insect to eliminate.
When silverfish move, their bodies tend to wiggle. This back-and-forth motion is similar to the wiggling of a fish. Some people have suggested that it is this wiggling that gave silverfish their name.
Silverfish can jump up to two feet vertically, which can make them difficult for humans to catch.
Other interesting facts about silverfish:
- They hate citrus
- They can live up to one year without eating
- They live up to 8 years
Silverfish can be very difficult to prevent, because they don't discriminate by location or even, for that matter, food. Homeowners or renters may start to see silverfish in their home at anytime. What's more, since one silverfish does not necessarily indicate a serious infestation, many people have a hard time catching their infestation in its early stages.
Homeowners with homes that are particularly ideal for a silverfish infestation can prevent a problem by changing the conditions where they live. By making simple lifestyle changes and by staying vigilant, people can prevent a silverfish infestation.
What Attracts Silverfish?
Knowing what attracts silverfish can make pest prevention easier.
One of the things that silverfish eat is dust, and another thing they eat is paper clutter, so homes that have a lot of clutter or that are not frequently cleaned are more likely to have a silverfish infestation. Homeowners can get rid of clutter by recycling, sorting, selling their items in periodic garage sales, and organizing their items.
Silverfish prefer darkness, which may be why they're nocturnal. This means that you can most often find silverfish in parts of the home that are usually dark, like the basement or garage. Parts of the house where daylight and artificial lights are turned on at night are less attractive to silverfish.
Another reason that silverfish can often be found in the basement is because they're attracted to places where they can live peacefully without being disturbed by people. In nature, silverfish are often found in logs and under rocks.
While silverfish can go a year without eating, they establish themselves in parts of the house where they can find food. Often, this is a basement or attic area, where clutter and dust are readily found.
Reducing Clutter and Food Sources
Unfortunately, silverfish eat the things that exist in most homes, like paper and dust. Reducing clutter and food sources can help keep silverfish away, but maintaining a dust-free, clutter-free house is very challenging. Fortunately, there are other ways to deny silverfish access to their normal food sources.
Keep Clutter Organized and Packed Away
Put stacks of paper, especially paper stored in basements or attics, in plastic tubs with tight-fitting lids. This makes the paper inaccessible to the silverfish and also makes it much easier to clean these spaces.
De-Clutter As Needed
Even better than storing paper and clutter on-site is removing the clutter altogether. There are many ways that this can be done.
- Hold regular garage sales
- Declutter on annual or semi-annual basis
- Recycle or give away items as needed
- Give away old clothes you no longer wear
- Repurpose items instead of putting them in storage
Cleaning helps eliminate the food sources that silverfish rely upon. It's not enough to perform superficial cleaning. Deep cleaning on a regular basis prevents dust from building up in the home. Pull out boxes and sweep behind them. Keep your closets clean by organizing them and then sweeping and dusting inside of them.
Launder curtains and shampoo upholstery. Use your vacuum to clean hard-to-reach corners, including dusty ceiling fan blades.
Pull Out Carpeting
Carpeting is a source of food for silverfish. In addition, carpeting tends to be a repository for dust and dust mites, which makes carpeting like a marketplace for silverfish. Removing carpeting from the home makes it easier to clean the house, and makes the house less attractive for silverfish.
Clean Your Air Ducts
Dirty air ducts distribute dust around the house when the HVAC system is turned on. Air duct cleaning services eliminate this dust and help keep the house cleaner.
Humidity is a major contributing factor to silverfish infestation. Silverfish prefer 75% to 95% relative humidity, which is much higher than the humidity levels in many homes. If your home's humidity is this high, there are many things you can do to fix this problem.
Run a Dehumidifier
A dehumidifier is a costly piece of equipment that reduces the moisture indoors. These devices use a lot of electricity and can sometimes remove too much moisture. If you're thinking about buying a dehumidifier, read product descriptions and be ready to spend more money for a high-end product.
Run the Vents
The most humid parts of your home, like the bathroom and the kitchen, should have vents that can remove moisture. Run these vents when cooking, bathing, showering and engaging in other activities that put moisture in the air.
Plumbing leaks and roof leaks can cause a variety of problems, including raising the humidity in the home. Fixing leaks reduces the water evaporating in the air.
Other ways to reduce moisture in the home include:
- Reduce the number of plants. Plants put moisture into the air, so keep plants to a minimum.
- Take shorter showers. Showering fills the bathroom with moisture, and that moisture can spread to other parts of the house when the bathroom door is opened.
- Switch heat sources. Some heat sources do little to control the humidity in the home, so switch to a heat source that reduces the amount of humidity.
You can keep track of the humidity in your home by installing a hygrometer. You may need multiple hygrometers in multiple parts of your home, especially if your home is large. For best indoor living conditions, aim for a humidity of around 40% to 50%.
What to Do When Moving Into a New Home
You can reduce your chances of infestation when you're moving into a new home.
Clean from Top to Bottom
Clean the home thoroughly before moving in boxes and furniture. Start at the top of every room and clean downward. For example, dust on top of the cabinets and ceiling fans first, then clean the walls, then clean the counters, and so on.
If the home has an unfinished basement, scrub down the walls and floors with a scrub brush and a combination of water mixed with a little bleach. Ventilate the area well to keep the area dry.
Remove Old Carpeting
Tear out any old carpet and plan on starting fresh. If you want to install new carpet, avoid materials that silverfish will eat, like cotton.
Reduce and Organize Clutter
Do what you can to get rid of clutter before moving into your new home. Throw away or recycle papers you don't need. Sell items in a garage sale before the movers arrive to help you out of your old home.
If your old home is infested with silverfish, do what you can to eliminate the infestation before moving into your new home, or you may bring the silverfish with you. Scrutinize any books, papers and clothing that may have been a meal for silverfish. Eliminate any insects from your possessions before moving.
Finally, when you do move into your new home, use plastic containers to keep your bills and papers organized. Avoid stacking papers in your new home.
Despite your best efforts, your home could still become infested with silverfish. Silverfish will eat anything and will live in many environments. Infestation could happen to nearly anyone.
If this happens to you, it's important to recognize the signs and know what to do about the infestation. Being prepared, working with the experts and using best practices at home is the best way to avoid a serious problem.
Signs of a Silverfish Infestation
One of the most notable signs of a silverfish infestation are actual sightings of the insects themselves. Since silverfish like the dark and they tend to like moist areas, many people do not notice silverfish when the silverfish first move into a home. You're most likely to see silverfish during a night-time visit to the bathroom, or in your basement, especially in the evenings. There are other signs that you have a problem, as well.
Silverfish shed their skin, mainly in their nymph and adolescent stage. These skins look like adult silverfish, but smaller. They're easy to miss, especially when the silverfish is in its youngest stages. However, these skins are a tell-tale sign that a home is infested, since the skins are usually only noticeable if there are enough insects around to create a collection of them.
Holes and Stains in Infested Materials
Silverfish eat all kinds of materials, including clothes and books. You should be able to see holes in these infested materials. Yellow stains and black flecks, similar to pepper, will also be visible on the infested materials. Since silverfish eat wallpaper, you may also see holes in the wallpaper on your walls.
Potential Consequences of Silverfish Infestation
Silverfish might seem inconsequential, especially when you consider that they live in the basement and don't bite, but there are many things about a silverfish infestation that can be problematic.
Silverfish are known to shed their scales, which mixes with the dirt and detritus found on the floor. This dander can exacerbate allergies, creating an unpleasant living environment.
Spiders eat silverfish. When silverfish move into a home, they bring with them the predators that would consume them. Therefore, homes that have silverfish often have spiders.
Damage of Personal Belongings
Most of all, silverfish can be damaging to items like books and clothes. Replacing items that have been damaged by silverfish can become expensive. In addition, it's not always easy to see from the outside that an item has been damaged. A person may not realize that their sweater has been ruined until they try to wear it. They may not discover that their book is destroyed until it's time to do homework. This damage to personal belongings can have a negative impact on quality of life.
Are Silverfish Dangerous to Humans? Common Myths About Silverfish
Their striking appearance with appendages that look like pincers have lead to some strange myths and beliefs about silverfish. Knowing the truth may become important, especially if your house has an infestation.
Do Silverfish Bite People?
No, silverfish have no ability to bite people. They do not bite in self-defense, nor do they bite people as food.
Do Silverfish Carry Diseases?
Silverfish are not known to have diseases that can be spread to people. The only diseases or bacteria they might spread are the kind on the outside of their body.
Do Silverfish Invade Kitchens?
Silverfish are attracted to foods that contain sugar and carbs, so there may be a variety of foods in your kitchen that would be attractive to silverfish. Coffee is one food in particular that silverfish like to eat, so it should be kept in a glass jar or tin, if at all possible.
Can Silverfish Crawl In Your Ear?
Silverfish are not known to crawl in ears, nor have they been known to lay eggs in people's ears. Bugs in general have crawled into ears and may cause ear pain, but this is not a common occurrence, and it is not something that silverfish are known to do.
Are Silverfish Poisonous?
Silverfish are not poisonous or venomous. They do not harm people, aside from potentially exacerbating their allergies and causing damage to their property. Of course, you'll still want to get rid of them.
How to Get Rid of Silverfish
Traditional poisons do not get rid of silverfish, so eliminating this pest is an ongoing process. Indoor and outdoor treatments are handled differently. If you're a homeowner who would like to eliminate silverfish from your property, you'll need to eliminate them from your home and yard. You'll find that a combination of lifestyle changes and working with a pest control company will be the best way to get rid of this problem.
Professional Pest Control
Professional pest control is the most effective way to eliminate silverfish. However, it's also the most expensive method of pest elimination, and may not be necessary for a home where only a few silverfish have been found.
Your pest control person may do many things to eliminate your silverfish problem. Pythrethrin is a common pesticide that many pest control people use to kill silverfish. Pythrethrin comes in liquid form and can be used to kill adult silverfish, but not their eggs. Your pest control person may also use products like diatomaceous earth.
Most important, your pest control person will be able to identify points of entry and possible places where silverfish spend time. By identifying these places in your home, your pest control person will be able to spray the pythrethrin strategically.
A good pest control person will also be able to make recommendations to you as a homeowner regarding lifestyle changes you can make to prevent silverfish infestation in the future.
How Can You Tell a Pest Control Person is Right For You?
You'll know to hire a pest control person when you've been able to identify multiple signs that you have an infestation in your home. For example, if you've seen silverfish and have also noticed that some of your clothes have holes, call a professional. If you've only seen one or two silverfish in your home, you may not need professional help unless your home has had an infestation before.
Not everyone is comfortable calling a pest control person. Some people balk at the prospect of paying a professional; others simply don't like the idea of someone using synthetic poisons in their home. For these homeowners, there are many natural solutions.
Make Jar Traps
Wrap the outside of several glass jars with masking tape, sticky side pointing out. Next, place the jars in locations where silverfish have been seen around the home. Place bread inside the jars. Silverfish will use the masking tape to climb into the jars, but will not be able to climb out after reaching the bread. Check the jars every morning for silverfish and eliminate them in whatever way makes you feel comfortable.
Spread Diatomaceous Earth
Diatomaceous earth is a natural product that is sold in home improvement centers and big box stores. It is made up of fossilized remains called diatoms, which are tiny aquatic organisms that lived millions of years ago. Diatomaceous earth is non-toxic to people but toxic to silverfish.
This product is commonly used as an insecticide because it removes the waxy coating on the outside of insects. When the waxy coating is removed, insects cannot retain water and eventually die of dehydration. Because diatomaceous earth is safe for people and deadly to silverfish, it is a go-to product used by many homeowners.
Sprinkle this product in doorways, around cracks in the wall, and in areas where silverfish have been seen.
Apply Cedar Shavings
Cedar shavings are said to repel silverfish. Spread them around doorways and in corners where silverfish have been seen. Since cedar shavings can make a mess, this solution is best utilized in parts of the house where you don't mind if cedar shavings are present, like in your basement.
Apply Essential Oils
It's said that silverfish don't like certain essential oils, such as the smell of lavender, lemon, and orange. Apply essential oils to cotton swabs, then swab your walls and floors with essential oil, particularly in the parts of the house where silverfish have been seen. This may help keep them away if they're not fully infesting your home. However, this is unlikely to keep silverfish away if they're already living on the premises.
Change the Environment in the House
Changing the environment at home is one of the easiest and most natural ways to prevent silverfish. This article has already outlined many ways this can be done.
- Reduce humidity
- Dust frequently and thoroughly on a regular basis
- Clean ducts
- Buy and use an air purifier
- Eliminate or reduce clutter
- Store paper, books and out-of-season clothes in plastic tubs
- Check the floor regularly for shed skin
For many people, changing the environment at home can only happen over time and it often requires a mind shift. People who instinctively keep a lot of paper or clutter in their house may have trouble letting go of their old items, or may have a hard time sorting through years of built-up possessions.
Sometimes it helps to have support from an expert. Hiring a professional organizer or even a professional cleaning person can make this job easier.
Common Products for Silverfish Control
Although many common insecticides will not kill silverfish, there are some products that homeowners can easily purchase that can control silverfish.
Boric acid is a natural insecticide and also a poison. Unlike diatomaceous earth, it is a poison for people as well as insects, so families with small children or pets should avoid using this product. Boric acid must be ingested by the silverfish in order to be effective. This product can be sprinkled on the ground or in areas where the insect is known to live. Since this is a poison, directions should be followed and it should be handled carefully.
Control dusts can be dispersed around an area to kill silverfish that come into contact with the dust. Control dusts are generally effective for many months. If you’re going to use control dust in your home, read the manufacturer specifications carefully to ensure that the product you choose will kill silverfish, since not all dusts are effective against this insect.
Liquid sprays are generally applied outside the home and at entry points where silverfish would gain access to the home. Some liquid sprays may be applied indoors along baseboards, but check to be sure before applying any liquid sprays inside the house.
Baits are designed to be attractive to silverfish. They must be ingested by silverfish, and once they are, they will die. Baits are often most effective indoors. If you’re looking for an outdoor product, read the manufacturer's notes to ensure the product is designed for outdoor use.
Not all standard insecticides will kill silverfish. Before spraying any insecticides inside your home or on your property, check the manufacturer’s instructions to determine whether your insecticide of choice is effective against silverfish.
Many aerosols come with a long tube-like applicator for easy application in small cracks and crevices. Be careful when spraying any liquids or aerosol products around the house. Avoid spraying anything that could be damaged by a staining liquid. Do not apply spray products to upholstery or carpeting unless the product specifically states that it will not damage these materials.
Prevention is Easier than Elimination
Though they’re not dangerous to humans, silverfish can be destructive and disturbing. If an infestation festers for long enough, silverfish can destroy books, photographs, wallpaper, magazines, junk mail, important mail, sweaters, blankets, carpeting and so on.
Don’t let silverfish take over your home or belongings. Protect your home and property by eliminating the conditions preferred by silverfish. Work with a pest control professional, and inspect your home regularly for signs of silverfish infestation. Taking these precautions can help you maintain a pest-free home.