Many a sleeper has awakened in the middle of the night to get a glass of water, turned on a light and spied an insect on his bed. Often, it's an open question as to just what that insect is. Many are easy to recognize, but some aren't. Silverfish are often in that difficult-to-identify category. And they just might be found on your mattress at night because they like to eat both cotton and linens.
The genus and species name of the Silverfish is "Lepisma saccharina." It's partly derived from the insect's love of sugars and starches (think "saccharine"). The silverfish is also known as a fishmoth or a paramite. Its common name is partly due to its silvery-light-gray-and-blue coloring. In addition, it's found pretty much all over the world, including North America and Europe. If you see one on your mattress, note its fish-like movements as it scurries away from you.
Silverfish are nocturnal insects, ranging in length from about a half-inch up to almost an inch. They're also elongated and present a flattened appearance, the better to get into dark tight places. All silverfish display three appendages at the tip of their abdomens called "cerci" ("sir kai"). One is parallel to its body while one faces left and the other right. Two long antennae protrude from the insects' heads. They have two compound eyes and they're wingless.
Silverfish are fond of carbohydrates, meaning just about any sugar or starch. That means they'll dine on just about anything that might include those substances, including many different kinds of glue. Carpeting, hair, dandruff, coffee and clothing often attract them. They'll even dine on cotton and linen, which is why you'll often find them around mattresses. Even leather and synthetic fabrics such as nylon aren't safe from them if they're hungry enough.
Silverfish have adapted to prefer moist, humid areas most of all. In homes, they're usually found in basements, closets and attics. However, anyplace where they can roam freely in the evening, like bedrooms, will be attractive to them. Those places are dark and there's sure to be hair, cotton and maybe even dandruff nearby. Wet or damp towels and clothing regularly left in a bedroom can also be attractive to silverfish.
Fortunately, silverfish aren't disease carrying and they're mostly a pest insect. They will, however, consume anything that appeals to them and can eat holes in mattresses, pillows and pillowcases, if allowed. Biological predators of these insects include common house spiders and centipedes. Natural control measures include the use of citrus sprays. Silverfish find citrus scents highly repugnant. Diatomaceous earth powder, which is a desiccant, also kills them through dehydration. Just sprinkle it wherever you think they're roaming around.