Buzz
Silverfish don't have the ability to fly or swim, but they can move quickly. ullstein bild/Getty ImagesIf you've ever rummaged through old boxes in your attic and discovered some silverfish, you may feel disgusted. But where do these pests come from, are they harmful, and how do you eliminate them?
Understanding Silverfish
You might be relieved to hear that silverfish cause far less damage than other pests like termites and are harmless to humans. As Doug Webb, the manager of technical services at pest control company Terminix, explains in an email, "Silverfish enjoy nibbling on materials like paper or fabrics with starch or sugar residues, such as wallpaper that uses starch-based glue." He also notes, "Clothing that has been starched is another favorite. They feed on the starch, but in doing so, they damage the fabric."
These flightless creatures used to find their way into books (as books were bound with glue), though that isn't the case anymore [source: Zoppi]. In earlier times, glues were made from animal byproducts or other natural materials that were rich in starch, sugar, or animal proteins.
"Modern adhesives, developed through chemical processes, no longer attract silverfish since they lack any nutritional content," Webb explains.
An Insect with Ancient Roots
Silverfish (Lepisma saccharina) have been roaming the Earth for over 400 million years and have remained largely unchanged since the time before dinosaurs.
"Aside from their size, silverfish have hardly changed over time," says Scot Hodges A.C.E., vice president of technical services at Arrow Exterminators, in an email [source: Arrow Exterminators]. "Their remarkable survival skills likely explain their minimal need for evolution. Some reports suggest they can survive for up to 6 months without food or water, as long as they have access to one of them."
The Silverfish's Anatomy
True to their prehistoric roots, silverfish are distinct in their appearance. Often described as having a "carrot-like" shape, these glistening gray creatures are covered in tiny scales, giving them their silvery look.
"The name 'silverfish' comes from their grayish to silver color and the way they wiggle as they scurry, resembling the motion of a fish swimming," says Webb. They continue to shed their skin into adulthood (you may have noticed their scales around your home).
A silverfish feasts on a book back in 1944, when bookbinding glue was made from natural ingredients.
Fritz Goro/The LIFE Picture Collection via Getty ImagesHere's a quick overview of their main anatomical features:
- Body shape and size: Silverfish have a teardrop-shaped body, tapering from a wider head to a narrower tail. Their bodies are long and flat, usually measuring around 0.33 inches (0.85 centimeters) in length.
- Exoskeleton and coloration: Their body is covered in a shiny, silvery-gray exoskeleton, with scales that give them a reflective, almost metallic appearance.
- Head and sensory organs: Silverfish feature a small head and long, slender antennae, which are highly sensitive to movement and scent. Due to their poor eyesight, they rely more on their antennae for navigation and detecting food sources.
- Mandibles: Silverfish have weak mandibles, making them unable to bite or harm you. Instead, they use their mandibles to scrape their food.
- Legs and mobility: With six jointed legs, silverfish are quick and agile, able to dart rapidly to avoid predators and search for food in a variety of environments within the home.
- Tail-like appendage: Silverfish possess three tail-like appendages: two lateral cerci and a central caudal filament. These "bristles" help them sense their environment.
Handling Silverfish Infestations
Unlike many other insects around the world, urban silverfish don't seem to offer any redeeming qualities. "They do not serve any beneficial purpose to man that I am aware of," says Webb. So, there's no need to worry about getting rid of them.
Silverfish aren't exactly eager to be found, as they prefer hiding in places that people rarely visit. "They can be found anywhere in the home, but they favor dark, undisturbed areas," explains Hodges. He notes that areas like crawl spaces, unfinished basements, and attics are ideal for silverfish. "These locations provide the perfect environment for them and also contain stored items that offer shelter and food." They typically enter homes to escape harsh weather and end up staying because the environment is so favorable for silverfish eggs.
These nocturnal pests take quite a while to reproduce to the point of causing an infestation. To prevent silverfish infestations, it's best to reduce the amount of clutter you accumulate. "The key to controlling them is to limit or eliminate harborage," says Hodges. "Large infestations are often tied to stored items and clutter."
If you do come across silverfish, cleaning them up isn't as bad as it sounds. "Vacuuming them is often the quickest and easiest way to get rid of them," says Frank Meek, technical services manager at Orkin.
He also recommends inspecting your home at least once a year to check for areas where silverfish might be hiding and where pests could enter. "If you store items in your basement or attic, make sure they are kept in hard plastic containers, not cardboard boxes. When moving stored items, inspect them first to ensure you aren't bringing these nocturnal pests into a new space," he adds.
Webb's team at Terminix typically identifies food sources that silverfish find irresistible, such as starch residue in utility rooms or food spills from starchy items like grains, pasta, and cereal. "It's also crucial to lower humidity in areas with high moisture by circulating air with fans, using dehumidifiers, or employing other methods to reduce moisture."
If silverfish have already become a significant issue, Meek recommends getting professional help. "If you notice signs of a silverfish infestation, contact a local pest control expert who can assess the situation in your home and determine the most effective extermination methods for your specific problem."
3 Species Similar to Silverfish
Here are a few species that could be mistaken for silverfish:
- Firebrats: These insects, with long, flattened bodies, resemble silverfish but are typically a brownish color instead of silver. They thrive in warmer environments.
- Jumping bristletails: Similar to silverfish, these creatures have an arched back and can leap. They are typically found in damp outdoor areas such as leaf litter and beneath rocks and logs, where they feed on decaying organic matter.
- Four-lined silverfish: This species resembles the common silverfish, with an elongated, silver-gray body and four distinct lines running down its back. They are typically found in humid environments, where they feed on carbohydrates and organic matter.
Although silverfish lack wings to flee from danger, they make up for it with surprising speed, which makes them tougher to catch or squish than you might expect.
