Though we might refer to any small being as an insect, there are actually different classifications, and the things that you thought were insects might not be. Insects, arachnids, and myriapods are three different classification groups and they all have different distinguishing features.

In this article, we are going to explain everything that you need to know about these three beings, so you can better understand what makes them different from each other. We are going to look at what they all are, what makes them different, and how to identify which bugs go into which category. 

What Is The Difference Between Insects, Arachnids, And Myriapods?

The difference between insects, arachnids, and myriapods is quite significant, and they are all different types of bugs that you can find. They are all classified differently by different characteristics. All three of these groups are entirely different, and you can identify them through their traits and features. We are going to explain everything that you need to know to be able to tell the differences between them below. 

What Are Myriapods?

Myriapods are both centipedes and millipedes, and some other small relatives. Centipedes and millipedes both look quite similar to one another as they have long bodies with lots of legs. They are actually related to insects are crustaceans, and they have a tough exoskeleton with jointed legs. 

Just like insects, myriapods have one pair of antennae, but they do also have more legs than insects do. All myriapods will have more than 20 legs, whereas other bugs will have much less than this. 

Millipedes typically have round bodies and they have two pairs of legs on each segment of their body. They move really slowly, and they are often found tunnelling through soil and dead leaves. Almost every millipede species is a decomposer, which means that they will eat things like dead leaves, fungi, and detritus. 

If they feel threatened by another animal, they can curl up into a ball and deliver a smelly toxic chemical to protect themselves. Myriapods are an ancient group of animals, and they were actually the very first to live on land. Before their arrival, the only animals that lived in the world were in the sea, so these were the first beings on dry land. 

Centipedes are usually flattened and they will only have one pair of legs for each segment of their body. They are also very fast predators that will eat any small animals that they can. Their bite is venomous, but they aren’t typically a danger to humans. 

Millipedes and centipedes both require a damp environment in order to survive and they spend most of their lives underground. 

How to Tell the Difference Between a Centipede and a Millipede

You can tell the difference between a centipede and a millipede because:

  • Millipedes have two sets of legs per each segment of their body, and these legs will be directly underneath their body, but centipedes only have one set of legs per each segment of their body, and they are positioned to the side of the body
  • Centipedes will typically eat insects after they have killed them using their venom, but millipedes will eat things like decomposing plants
  • From a side view, centipedes have a flatter body and millipedes are much more rounded
  • When they feel threatened, a millipede will curl up into a ball and release a toxic secretion, but a centipede will bite its target and run away quickly

What is An Arachnid?

Arachnids are spiders, harvestmen, mites, and ticks. Every arachnid will have eight legs and they don’t have antennae like insects. Their bodies are divided into two different sections, which are the cephalothorax, which can be found in the front, and the abdomen at the back. 

Sometimes, small arachnids such as mites and harvestmen will have these two bodily sections so close together that you can’t see the separation. There are no arachnids that have wings, but there are spiders that can float in the wind by using long strands of silk. There are lots of arachnids that use silk, and they can do so to help them catch prey or for reproduction. 

Arachnids will lay eggs and they have very simple development. Some arachnids, like mites, will change often through their different stages of life. Arachnids are also part of a larger group that is called arthropods, which includes insects, myriapods, and crustaceans. All arthropods will have an exoskeleton and legs that are joined. For them to be able to grow, they will have to shed their entire exoskeleton at the same time, which is often referred to as moulting.

There are hundreds of thousands of different species of arachnids, and they are found in almost all types of land habitats. There are even some arachnids in water habitats. Something that is interesting to know about them is that they can only eat liquid food as they can’t eat any solid food. When it comes to mealtimes, they will squirt digestive chemicals into their prey and suck out the juice from them.

Arachnids are predators, and they will hunt down insects and other invertebrates, except for mites. Mites will feed on lots of different things, like fungus, plants, dead animals, bacteria, and other invertebrates.

What Is An Insect?

An insect is a really small animal that can come in many different species. Insects are all invertebrates as they have no backbones, and the majority of them will walk, though there are some that can fly or jump.

All insects will need food, air, and water to survive, and they will have either an exoskeleton or a hard shell-like covering on the outside of its body. Insects typically have three main parts of their bodies, which are the head, thorax, and abdomen. They also have a pair of antennas on the tops of their heads. 

What Bugs Are Crustaceans?

Woodlice are among the crustacean family, which is a group that also includes crabs, lobsters, and shrimps. Unlike many other crustaceans, woodlice do not live in the water, and they prefer to live in damp places. Crustaceans have two pairs of antennae, and their bodies consist of the head and the abdomen.