Tarantulas are strange creatures. Just ask any person who has cared for a tarantula for any period of time. We all know that tarantulas sort of do their own thing. They are strange but nonetheless interesting creatures.
But what exactly are they? Are tarantulas an animal, and if so, what kind of animal? Are they an insect or something entirely different?
Are tarantulas insects or animals? Tarantulas are animals but not insects. All wild bred and captivity bred (pet) tarantulas are animals because they belong to the biological kingdom Animalia. However, tarantulas are not insects because they have a different body composition and belong to the class Arachnids.
In order to fully understand the slight nuances between the different terminologies people use, we need to get a little more in-depth.
In this article, I explain the subtle differences between insects, animals, and where exactly tarantulas fall in the grand scheme of things. Let’s take a look.
What Is the Difference Between an Animal and an Insect?
In order to make sense of things, let’s first start with what these words signify and refer to. Then we will be able to better understand the meaning behind each term.
What Is Considered an Animal?
According to the Cambridge Dictionary, an animal is “something that lives and moves but is not a human, bird, fish, or insect,” but we also find a second meaning, which is “a living thing that can move and eat and react to the world through its senses, esp. of sight and hearing”.¹
According to the Merriam-Webster, an animal is “any of a kingdom (Animalia) of living things including many-celled organisms and often many of the single-celled ones ( . . . ) having the capacity for spontaneous movement and rapid motor responses to stimulation”.²
As we can see so far, animal is a word that has a very broad meaning. Almost anything that moves and lives can be considered an animal, including humans. Now let’s take a look at insects.
What Is Considered an Insect?
According to the Cambridge Dictionary, an insect is “a type of small animal with six legs, a body divided into three parts, and often two pairs of wings, for example, an ant, beetle, or butterfly”.¹
According to Merriam-Webster, an insect is “any of a class (Insecta) of arthropods with well-defined head, thorax, and abdomen, only three pairs of legs, and typically one or two pairs of wings”.²
We can also see another definition of an insect, which is “any of numerous small invertebrate animals (such as spiders or centipedes) that are more or less obviously segmented —not used technically”.²
Now we have a good description of what insects are, including their unique body features and the fact that they belong to the class Insecta. Let’s take a look at tarantulas now.
What Is Considered a Tarantula?
According to the Cambridge Dictionary, a tarantula is “a type of large, hairy spider (= creature with eight legs), some of which have a painful bite”.¹
And according to the Merriam-Webster, a tarantula is “any of various large, typically ground-dwelling, hairy, mygalomorph spiders (family Theraphosidae) ( . . . )”.²
You may have noticed that the Merriam-Webster definitions go into more detail. Each one of the definitions also mentions something of particular interest that holds the key to understanding if a tarantula is an animal or an insect.
Tarantulas are defined as spiders—which is the last thing that we need to research.
What Is Considered a Spider?
According to the Cambridge Dictionary, a spider is “a small creature with eight thin legs that catches insects in a web”.¹
And according to the Merriam-Webster, a spider is “any of an order of arachnids having a short, usually unsegmented abdomen linked to the cephalothorax by the pedicel, chelicerae modified into poison fangs, and two or more pairs of spinnerets at the posterior end of the abdomen for spinning threads of silk ( . . . )”.²
Now that we have gotten to the bottom of it, we need to explore a few more things.
As you can see, spiders do have a few unique features that separate them from other animals. However, we can also see that they belong to the class Arachnids, which is an important piece of information.
This is what we will explore below.
How Are Animals and Insects Classified?
Over the years, people have noticed that not all animals are created equal. This is how, eventually, people tried to put everything into order and tried to categorize animals into different groups according to their unique features and characteristics. Those groups will have sub-groups, which can have subgroups of their own and so on.
In biology, living organisms are separated and organized into different groups or, more precisely, ranks, called taxonomic ranks. The taxonomic ranks follow a particular hierarchy.
The highest taxonomic rank, which encompasses all organisms, is called domain, also known as super-kingdom.
The domain is divided into kingdoms. The number of domains can vary from one to three, and the number of kingdoms can vary from three to eight, depending on which classification system is used.
Generally speaking, living organisms are often divided into animals and plants, which is a concept that has been around for thousands of years.
Animals fall under Kingdom Animalia, and Kingdom Animalia is divided into several different phyla, which is the third taxonomic rank.
One of those phyla is called Arthropods, and arthropods are divided into several different classes of animals:
The animals that belong to the Arthropods group are of particular interest to us in this article because this is the key to finding out if tarantulas are insects.
Are Tarantulas Classified as Insects or Animals?
Tarantulas are spiders, and spiders are part of the Arachnids group. This puts them in the Animal Kingdom, which is why they are considered animals. To this group also belong ticks, scorpions, mites, harvestmen, and other animals.
Arachnids are usually eight-legged, have a body that is divided into two parts, and are usually terrestrial invertebrates. Arachnids do not have wings, antennae, and cannot chew food.
Insects, on the other hand, as we have established, are a little different. They have a body that has been segmented in three parts, and usually have two wings and six legs. This makes insects very different from arachnids (and thus very different from tarantulas).
This is why we have an entirely separate class that is named Insects (or Insecta), where those little creatures belong.
In other words, insects and spiders belong to the same Phylum called Arthropods. However, they belong to different classes of arthropods. Spiders are not insects or bugs, and insects are not spiders, but both tarantulas and insects are animals as they belong to the Animal Kingdom.
What Is the Relationship Between Tarantulas and Insects?
Another way to quickly discern tarantulas from insects is to take a different point of view.
Here’s what I mean.
There is a specific connection between insects and tarantulas. Although both tarantulas and insects are animals, they are not on the same food chain level.
The relationship between tarantulas and insects is quite different, in fact. Tarantulas are carnivorous and actually eat insects, among other small animals. Tarantulas will readily eat grasshoppers, crickets, cicadas, caterpillars, roaches, mealworms, king worms, and even other spiders.
So a tarantula will be considered the predator while the insect the prey.
That is not to say there are no insects that can kill a tarantula.
A good example is the tarantula hawk wasp—a huge wasp that can grow up to 2 inches in length and is known as a fearsome predator that can kill not only tarantulas but mice, small birds, and lizards.
Should You Call a Tarantula an Insect or an Animal?
So what does that mean to our tarantula? Tarantulas are arachnids, which is a very different thing than an insect. Tarantulas are animals, but they are not insects. So can we call a tarantula an insect?
Some people do use the word insect for referring to spiders as well, and although this may be lexically correct, to a certain degree, it is not technically correct as tarantulas are not insects.
Not everybody will be confused if you call a tarantula an insect, and they will know what you mean. However, tarantula owners may get slightly irritated if somebody calls their tarantula an insect. This is why it is more appropriate to call the tarantula a spider instead of an insect.