Silverfish is a species of fish-shaped insect. These insects have grey coloring and they move similarly to fish alternating side to side movements even when moving forward.
These insects are considered a pest for multiple reasons.
Silverfish eat cellulose – silverfish digest starches and dextrin they eat from book pages, wallpaper, clothes, carpets, hair, and sugar.
Silverfish contaminate food – while not known for transmitting diseases, silverfish contaminate food around the house.
Humans should not be specifically afraid of silverfish as they don’t bite.
What Are Silverfish?
Silverfish are primitive insects of a gray color. They have 6 legs and a fish-shaped body. These insects are also known as wingless because winged ancestors haven’t been tied to the genus.
Silverfish are often compared to fish by movements and body shape. They have a wide body at the head which gets narrow towards the tail.
40 species of silverfish are found in the US from the hundreds of species found around the world.
What Do Silverfish Look Like?
Silverfish are variating size insects. It grows to a maximum size between 13 and 25mm. Its body is known for tapering towards the abdomen.
The bugs have 3 long appendices which resemble tails and 2 long antennae.
Silverfish are known for their metallic-gray scales which resemble the aspect of fish.
This resemblance is also seen in the wiggling movements or the side to side movements of the insect which resemble fish movements in the water.
Known for their agility, silverfish have a 2-3 years lifespan.
Silverfish prefer humid environments. They are often found around the house in the basement or bathrooms.
They require 75% minimum humidity to thrive.
These insects make their way inside US homes where they cause damage by chewing various objects such as clothes and paper.
Habitat and Distribution
Silverfish represent one of the oldest insects in the world.
The primitive nature of silverfish is seen in the evolution line of the species. These are only the second in line with the first insects in the world that lived hundreds of million years ago.
Silverfish are present in North America, Europe, Africa, Australia, and the Pacific in regions with high humidity.
These insects can be found in areas of homes with high humidity of at least 75%.
Bugs That Look Like Silverfish
Some bugs are very similar to silverfish. Even different species can have a similar appearance as follows.
Firebrats are bugs that mostly resemble silverfish. Both firebrats and silverfish are often found as pests in similar areas such as restaurants.
Both these species prefer high humidity environments with different preferences in temperature.
Silverfish prefer cool temperature while firebrats prefer warm temperature. As a result, firebrats are often found in or around ovens while silverfish are found in basements.
Both types of bugs are eliminated from homes and businesses by first lowering indoor humidity levels.
Physical characteristics are also close for these species.
Firebrats are small bugs that can grow up to 0.5 inches. They are part of the hexapod genus and they are known for a cylindrical tapered body similar in shape to silverfish.
Firebrats have a wider body at the head and a narrower body at the abdomen.
3 long appendices that look like tails are also seen on firebrats, similarly as on silverfish.
Firebrats are also found outdoors under logs, rocks, and leaves. They make their way inside as pests in search of food, but they are considered somewhat harmless compared to other more serious pests.
A typical firebrat lives a long life of up to 5 years. It lives almost twice as much as the typical silverfish.
2. Jumping Bristletails
Part of the Apterygota, Jumping Bristletails gets their name from their ability to jump. These bugs use their long tails to act as trampolines and jump high in the air.
Jumping Bristletails jump up to 12 inches in the air for defensive purposes.
These bugs are very similar to silverfish both based on their long history and based on their physical appearances.
Jumping Bristletails have a primitive background that goes back millions of years.
The insects show a cylindrical body that tapers towards the tail. There are 3-tail extensions that run from the abdomen.
One of them is used to propel the insect high in the air.
Unlike silverfish, these insects show detached scales that cover their body. These are believed to have a dual purpose.
Scales on their body add protection in front of predators. But they also help these insects fight dehydration when facing extreme weather.
It’s estimated the species goes back 397 million years ago. Its primitive nature is believed to be seen in its gliding mechanism.
These insects know how to glide when they move from an upper to a lower position.
It’s believed this movement was one of the stepping stones for insects that had wings and the ability to fly.
Today, Jumping bristletails live in large numbers in North America and Europe.
They’re also seen across South America, Africa, Asia.
3. Two-pronged bristletails
This species of ancestral insect is known to live in the ground. Without vision, Two-pronged bristletails still resemble silverfish with their 2 long cerci.
These bugs are known for having a segmented body in various colors and even in translucent versions. 7 families or sub-types of bugs exist among the Two-pronged bristletails.
Its wide variety means it’s found in multiple colors and different sizes. From 2 to 9 mm, Two-pronged bristletails have different sizing.
There are over 80 species of Dipluran bugs, most resembling silverfish by their long cerci.
Some of these bugs are plant-eating. While not all of them are known for using their cerci as pincers, it’s estimated Two-pronged bristletails of the Japygidae family are believed to use these against prey.
Other bugs of the species simply use cerci to make their way around since they can’t see.
Some members of the Campodeidae sub-family are known to rely on cerci to establish ground vibrations and make their way below the ground level.
The species is known for a very wide distribution around the world. It can be found on the ground on most continents.
These bugs are mostly found in damp soil. They are occasionally seen under piles of leaves or hiding in humus organic matter.
It’s believed the presence of these bugs indicates rich soils appropriate for farming as they cannot live in grounds depleted of organisms they feed on.
Earwigs are known as creatures that crawl into the ears of people. While this is a superstition, earwigs are creatures that resemble silverfish considerably.
Both earwigs and silverfish have elongated bodies. Earwigs grow to a size between 5 and 20mm and they’re also mainly nocturnal.
Most earwigs are herbivorous although data are showing they can also eat insects.
One of the biggest similarities between earwigs and silverfish is their cerci of pincers at the end of the abdomen.
These pincers are used differently by males and females but they’re mainly considered for feeding.
Males use pincers to hold on to food and even for catching insects. Females are known to use pincers similarly plus during the mating ritual when they hold partners with them.
Females also use pincers when taking care of their young.
These pincers can be raised above the abdomen. Both male and female earwigs are known for raising these pincers in the air similar to how scorpions raise their tails.
Centipedes are also highly similar to silverfish, particularly in movements.
Most US centipedes can differ in size and looks. The Giant Centipede is the largest of its type in the country.
It grows to 11 inches and it exemplifies the species as it’s easy to see its body parts. These centipedes also have cerci and they’re known for inflicting painful bites on people.
Centipedes in North America are burrowers. They prefer to dig in the moist ground looking for food such as worms.
But centipedes exhibit a similar method of moving their elongated bodies to silverfish even if they have more legs than centipedes (most centipedes have at least 10 legs).
The worm-like movements of centipedes are often associated with the movements of silverfish.
These movements together with the cerci at the end of the abdomen make centipedes similar to silverfish.
Isopods are crustaceans that comprise more than 10.000 species. Most of them live both on land and in freshwater.
Isopods grow in various sizes from 10mm to 14 inches.
Most isopods resemble silverfish through a flattened body and a shiny gray look. However, isopods can also be white, red, green, and brown.
The body of isopods is made from segments, just as the body of silverfish.
Isopods such as woodlice live terrestrially. Most crustaceans can’t live on dry land.
Defensive techniques are also among the biggest differences between isopods and silverfish. Isopods can roll themselves up into a ball.
This ability is also used to maintain high moisture levels for the body.
Some gray cockroaches resemble silverfish. Cinereous cockroaches are an example of gray bugs of the genus that resemble silverfish.
Cockroaches are known for having various colors. From black with white marks to common amber-brown thumbnail-size cockroaches, they come in many species and colors.
Cockroaches are some of the bugs people are most informed about as they are household pests.
They feed on human food and other insects.
Carrying various pathogenic microbes is one of the main problems associated with cockroaches.
Termites can have similar sizing and coloring to silverfish. Most termites are rather small but they can grow up to 15mm.
Colors vary considerably in termites from brown to gray, similar to the color of silverfish.
Termites are organized in successful casts. They form colonies and they are found all around the world, particularly as pests.
Termite colonies are led by queens. Most queen termites live up to 50 years making them the insects that have the longest lifespan.
9. Lacewing larvae
These bugs are known for an elongated body with pincers, similar to silverfish.
Lacewing larvae are known for injecting venom into prey. They eat almost any other soft insect they can find.
Bugs of the species are known for eating up to a few hundred bug pests each week.
These bugs are sometimes known as alligator bugs as they move similarly to alligators. They are also known for a flattened body similar to silverfish.
10. Carpet beetle larvae
Carpet beetle looks similar to cockroaches. However, carpet beetle larvae look similar to silverfish. The larvae have a similar gray, white, and brown body with long hair.
The movements of the larvae resemble the slow lateral movements of silverfish.
Carpet larvae are among the most serious pests. Adult carpet beetle lays up to 100 eggs at a time which mature quickly within 10 days.
Springtails are some of the smallest bugs that resemble silverfish. They measure only 0.2mm to 10mm which makes them hard to spot at first.
Springtails can jump.
Physical characteristics include a segmented body with 6 legs. Just as termites, springtails can hardly see or even not see at all. They can only distinguish light from the darkness.
Just as silverfish, springtails can be found in moist soil, compost, and under leaves. These small insects aren’t harmful to humans as they aren’t classified as pests.
Even more, springtails can be beneficial at times. They eat bacteria and fungi as well as decaying vegetation.
These bugs can also be harmful to certain plant species around the garden. They are sometimes known for chewing plant roots.
Similar to silverfish, springtails have silver scales on their bodies. These scales also come in other colors.
Some springtails have orange or white scales.
There are hundreds of springtail species in the US.
Bugs that resemble silverfish have similar physical traits and sometimes other similar characteristics such as movement patterns. These bugs can be silver or gray and they can have segmented bodies.
Many bugs that resemble silverfish also share a similar high moisture habitat in soils or homes as pests.