When dealing with insects it’s always important to know exactly what type of problem you have on your hands. Solutions and products that work on one type of insect are often ineffective on others, often even if they are a part of the same overall family group. Additionally, look-alike insects can often have drastically different effects and consequences on your home, property, and health. That goes for silverfish and for insects that look like silverfish as well.
Silverfish are a rather unique type of insects in that they grow without changing their body structure (i.e. without metamorphosing), they reproduce slowly, and they live longer than most other insects. They also have a relatively unique body structure, but they can still be mistaken for some other insects. In this article, we’ll cover exactly what silverfish look like and which are some of the insects similar to silverfish.
What do silverfish look like?
Silverfish are wingless but they are quite fast-footed. They have two long antennae on their heads as well as three slender “bristles” springing behind them to give them an even creepier look. They have tapered carrot-like bodies and are covered with silvery and shiny scales. Their coloring, together with their slivering and quick movements are what has given them their common name – silverfish.
Adult silverfish can range from a centimeter (or half an inch) up to two and a half centimeters (or a whole inch). Young silverfish nymphs have the exact same body structure but are smaller in size and paler in color. The silverfish don’t go through larvae or pupa stage and hatch as almost fully-developed silverfish. The eggs themselves are about 0.75 centimeters (0.03 inches) long.
Silverfish prefer warm, shady and moist environments with bountiful food nearby even though they are known to travel long distances for food if need be. They are also strictly nocturnal which is why we rarely see them even when they’ve already settled in our homes.
Which are the most common insects that look like and are often mistaken for silverfish?
As unique as silverfish are in many ways, there are still silverfish look-alike insects. If you need to be certain of what you’re dealing with, here’s a quick list of the bugs that look like silverfish:
Firebrats, or as they are also known, Thermobia domestica, are members of the same insect order as silverfish – Zygentoma. As a result of that, they are very similar to their silverfish cousins. They are also flattened, wingless insects that are fast on their feet. They share similar mating and feeding habits, and they are also nocturnal. In terms of their appearance, Firebrats are darker in color than silverfish which is what some people refer to them as the “black silverfish like a bug”. They also prefer even warmer temperatures than silverfish so they can often be found near furnaces or boilers.
Bristletails is the common name for the hexapods of Zygentoma order and the Archaeognatha (or Microcoryphia) order. In that retrospect, silverfish are technically bristletails as well. Other bristletails can vary greatly in size but they all share similar body shapes and origins. Most bristletails are outdoor insects and will rarely come close to your home or property as there’s nothing of interest for them there. The same really goes for most silverfish as well, since only several of the silverfish sub-species are found indoors. If you find a silverfish looking bug outside, however, it can be any type of bristletail.
For a less of a silverfish-like bug, the earwig can also be mistaken with a silverfish by the untrained eye although it’s a very different insect. Earwigs are not bristletails at all and instead of three distinctive bristles on their back, they have two menacing-looking pincers. They are also dark-brown in color and are mostly outdoorsy creatures. They may look unpleasant but they are mostly harmless to humans unless you bother them in which case they might try to defend themselves.
Earwigs feed on the decaying plants in your garden and may sometimes feed on live or dead insects. Earwigs will only try to break into your home during the winter months when they are looking for shelter. Their most significant commonality with silverfish is that they are both about half an inch long. Also, both insects are said to crawl into people’s ears when they sleep but in both cases, this is a complete myth.
Like the earwig, centipedes do have a lot of physical differences when compared to silverfish from up close. Just like earwigs, however, they are usually seen from afar and at a greater distance they can be easily mistaken for silverfish. A complicating factor is that both silverfish as well as a lot of centipedes are rather quick on their feet and hide when you try to approach them.
Nevertheless, from up close, centipedes are quite distinguishable from silverfish as they have up to 30 legs and more. It’s also worth mentioning that centipedes actually like to eat pests such as silverfish, roaches, and ants.
Different types of lice such as booklice or woodlice can be mistaken for silverfish in that they have the same grey coloring and an approximately similar length. They have a different body shape, however, and are not nearly as fast as silverfish, firebrats or other bristletails.
While a lot of insects can be mistaken for silverfish from afar, these ancient insects do have multiple distinctive characteristics that can make them stand out when viewed from up close. Only firebrats or other bristletails can realistically be mistaken for silverfish when examined carefully and even then, the several common types of indoor silverfish are relatively easy to identify.