What makes an insect an insect

Feb 01, 2021
What is an insect anyway? Check out just what makes these skittering, buzzing, and chirping animals so amazing. Then, join us for our February Nature Night to learn even more about the importance of insects!

By Rebekah Ratcliff

A bee in flight. Photo: Kris Kristovich.
A bee in flight. Photo: Kris Kristovich.
Flying about overhead, buzzing next to us, or crawling about beneath our feet, insects are just about everywhere! Insects make up more than 80% of all known species on earth, and many scientists believe that there may be even more unknown insects than there are known ones. Currently, for every one human living, there are more than 200 million insects. In case that number is a hard one to grasp, scientists say at this very moment there are 10,000,000,000,000,000,000 (10 quintillion) living insects around the world. What I’m trying to say is: insects are kind of a big deal!

With all those insects skittering about, it can be hard to keep track of what’s what. Here’s some insect 101! Insects are invertebrates (without a backbone) that have a hard outer casing called an exoskeleton. Insect bodies are divided into three parts: head, thorax, and abdomen. Adult insects have six legs, and most adult insects also have wings! 

There are over a million species of insects in the world. To keep things straight these species are broken up into different groups. Here’s a look at the 7 main groups of insects:

  1. A yellow beetle. Photo: Joan Amero.
    A yellow beetle. Photo: Joan Amero.
    Beetles. Beetles make up about half of all insect species. Beetles start their lives as grubs and later grow into their adult form with robust shells and hard wing casings. The largest known insect is the South American longhorn beetle (Tytanus giganteus) At 25cm long, it's about as big as an adult human’s hand!

  2. Bees, wasps, and ants. Bees, wasps and ants are all members of the group Hymenoptera. Many of us have seen these insects buzzing about, but did you know that they often have two sets of wings?

  3. True Bugs. The buggiest of all bugs! Insects in the true bug category are mostly known for their ability to drink liquid food by using their sharp and straw-like mouthparts. Assassin bugs use this adaptation to their advantage so they can drink the blood of other insects (yes! Insects have blood!).

  4. Cercropia moth. Photo: Land Trust.
    Cercropia moth. Photo: Land Trust.
    Butterflies and moths. Butterflies and moths are the big-winged wonders of the insect world. Known for their incredible metamorphosis, butterflies begin their lives as caterpillars and later transform into the colorful winged beauties we see fluttering about!

  5. Flies. Flies only have one set of wings and generally have fuzzy hairs covering their bodies. There are all kinds of flies. Have you ever heard a horse-fly coming and bolted away to avoid a bite?

  6. Crickets, locusts, and grasshoppers. These insects have strong legs and are known for their hopping power! You might also know them by the noise they make when rubbing their wings or legs together. Did you know that noise is actually their mating call?

  7. A dragonfly in flight. Photo: John Williams.
    A dragonfly in flight. Photo: John Williams.
    Dragonflies and damselflies. Dragonflies and damselflies have long slender bodies with large eyes and outspread wings. Generally, dragonflies have larger bodies. Though you will see them zipping about in the air, dragonflies and damselflies begin their lives (as nymphs) underwater!


Beetles, bees, and beyond! There are so many insects living in the natural world to explore and discover. Want to learn more?
Join the  Land Trust and Dr. Tara Cornelisse for our February Nature Night: The Importance of Insects on February 17th at 7pm. Register now for this virtual event.

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