Scientists have identified about 1,744,204 distinct species of insects. That’s an impressive number, but a mere drop in the bucket compared to the number of species waiting to be discovered. The total number of insect species is estimated to be between 5.5 million and 30 million.
But are insects technically animals? Are they something else entirely? Today, we’ll discuss insects and how they’re classified in the animal kingdom.
Is an Insect an Animal?
Scientists believe there are between 5.5 million and 30 million species of insects on earth.
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Yes, insects are animals.
Looking at our handy Animal Classification Guide, we see the highest level of taxonomy is ‘Domain.’
Based on their taxonomy, insects have been determined to be animals.
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Archaea, Bacteria, and Eukarya are the three taxonomic domains. The first two include mostly single-celled organisms, but only Eukarya features organisms with cellular nuclei. Does that mean everything in Eukarya is an animal? No. To reach that point we need to move down a rung to ‘Kingdoms.’
After all, trees are multiple-cell organisms with nuclei, but a tree is obviously not an animal! That’s why at a ‘Kingdom’ level there is a classification known as Animalia, or animals. Species grouped in animals share a number of common traits:
- Reproduce sexually
- Breathe oxygen
- Consume organic material
- Are able to move
With a low number of exceptions, all animals meet these basic criteria. Insects are among animals in this regard.
What Percentage of the World’s Animals Are Insects?
In total, invertebrates, including arachnids, crustaceans, insects, and other species, make up 96% of all identified animal species.
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Now that we’ve established that insects are animals, let’s dig into just what percentage of the animal kingdom is insect-related.
The short answer: A lot. Today, there are about one million described species of insects. That’s about 70% of all animal species. In total, invertebrates are 96% of all identified animal species.
Most importantly, the percentage of insects compared to other animals should continue to grow in the decades to come. Climate change in particular is a major factor in the estimated growth of insect populations. While other animals will have to contend with issues like loss of habitat and food sources due to higher temperatures and more extreme weather events, insects will thrive. Scientists posit that as global temperatures rise, so will insects’ metabolic and reproductive rates.
What is the Largest Family of Insects?
Which insect dominates in numbers? Believe it or not, the largest family of insects is the beetle family. An estimated 1.5 million species of beetles exist alone! But even that number is not a given — according to one study, there could be over 2 million species.
Of those numbers, scientists have only described 350,000 different beetle species. So, beetles are estimated to make up at least 40% of the insect kingdom (and that’s a conservative estimate — some experts put that number at 50%)!
Different Types of Insects
Walking sticks, more commonly known as the stick bug, sway back and forth to mimic a branch in the breeze.
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There are 9 basic orders of insects:
- Coleoptera: beetles
- Dictyoptera: cockroaches and mantids
- Diptera: flies
- Ephemeroptera: mayflies
- Lepidoptera: butterflies and moths
- Hymenoptera: ants, bees, and wasps
- Odonata: dragonflies and damselflies
- Orthoptera: grasshoppers and katydids
- Phasmida: stick insects
This is not an exhaustive list of all the insect types — there are almost 20 more orders of insects. Other orders include insects like fleas, termites, earwigs, sucking lice, and silverfish. The list goes on, and it’s no wonder there are over 1 million identified species of insects!
Bugs vs. Insects: What Are The Differences?
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You might be asking yourself: “What’s the difference between an insect and a bug?” Like insects, bugs are definitely animals, but the question of how bugs and insects differ might be on your mind.
The word “bug” is often informal. Many people will simply use the word “bug” to refer to any crawly creature with legs. Under this definition, even animals that aren’t insects would qualify as bugs.
A more formalized definition of a bug is an insect whose mouthparts pierce and suck. The order of insects that fall under this definition of the word “bugs” is Hemiptera. Examples of bugs under this more formalized definition include everything from bed bugs to cicadas, to aphids, which are small sap-sucking insects.
How Many Insects Are in the World Today?
Ants are one of the most numerous groups of insects on the planet.
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With insects on every non-Arctic landmass across the world, you might be wondering: “How many insects are in the world?”
It’s nearly impossible to count insects, but scientists estimate their populations and most believe that roughly 100 trillion ants roam the world! Put another way, their “biomass” may be as much as all humans combined — even with our weight differentials factored in!
The total number of every type of insect was estimated by the Smithsonian at 10 quintillion. If we write that out, the number of insects in the world today is 10,000,000,000,000,000,000 insects on Earth!
