What is an insect?
Ask your kids to describe insects. Their answers may be very general or more specific, so depending on what you feel they already know about insects, you will probably want to pick and choose which parts of this Science Lesson you use. You might also want to use our Insect Activities for PreK-2 to give your kids more hands-on experience!
Help your kids write a list of every insect they can think of. Younger ones (preschool and kindergarteners) might want to draw a picture list, write their list on the chalkboard, or dictate their list for you to write out. Encourage them to include anything they think is an insect since the goal of this activity is to develop thoughts. As your study continues, they will be able to look over their lists again and cross off any items they included at first that are really not insects (such as spiders or roly-polys).
How can you tell an insect from a bug or other creepy-crawly creature? Ask older kids (first and second graders) to describe characteristics that insects have in common. Younger kids can do this too, just get them started with some examples, such as ‘insects have eyes’ or ‘insects do not have tails.’ See the Insect Anatomy section for more ways to tell.
Visual learners will especially benefit from browsing nature magazines, books, encyclopedias, or the internet for pictures of different insects. (A Google image search for ‘insects’ will bring up some great photos.) Have them try to find a picture of each insect on their list or ask them to find one picture that shows each of the characteristics they mentioned.
How big are the insects you have seen? (Get younger kids to show you with their hands; older kids might estimate the size of particular insects.) Some adult insects are less than 1 mm long; that’s really tiny! On the other hand, some rare stick insects in South America can grow all the way up to 36 cm (about 14′) long. (Show the contrast between how big and small these dimensions are on a ruler.)
Do insects have bones? Insects do not have a backbone like humans and many other animals do. In fact, insects do not have any bones; they have a hard exoskeleton instead. ‘Exo’ means outside, so that means that the skeleton is on the outside of the insect’s body instead of on the inside like in our bodies. Did you know that insects are related to crabs and lobsters, which also have exoskeletons?
Thinking Scientifically: Animals that have a backbone are called vertebrates – can you think of any vertebrates?. Any animals that do not have a backbone, like insects, are called invertebrates.
All insects have three main body parts: a head, thorax, and abdomen. It’s important to know these parts in order. It helps to think of the thorax as being sandwiched in between the head (which is at the top just like your own head) and the abdomen (at the bottom).
Head: An insect has a small head that is a lot like your own head because it holds the insect’s brain, eyes, and mouth. Insects also have special feelers called antennae that stick out of the top of their heads. They use their antennae to smell and feel because they do not have noses and hands like we do.
Thinking Scientifically: You may have heard the word antenna before, but have you ever heard anyone say antennae (pronounced: an-ten-I)? Did you know that ‘antennae’ is just the plural form of the word ‘antenna’? When we say ‘antenna,’ we are talking about one and when we say ‘antennae,’ we are talking about two or more, just like when we say ‘shoe’ we are talking one shoe, and when we say ‘shoes’ we are talking about a pair of shoes.
Eyes: Insect eyes are much different from human eyes (called simple eyes). In fact, insects do not even see things the same way we do! They have two compound eyes with many different lenses to see out of instead of just one lens in each eye like we do. Each compound eye can have anywhere from 2 to 30,000 different surfaces that are very sensitive to light. Compound eyes cannot see very much detail or things that are far away. They can see extremely quick movements and things that are close to them, though. If insects did not have compound eyes, they would have a very difficult time surviving and finding food! Have you ever tried to swat a fly? What happened when you got close to it? It probably flew away the second you got close enough to swat it. That is because a fly’s compound eyes bulge out of its head so it can see motion all around its body and see when you are coming closer to it.
Thinking Scientifically: Some insects, like grasshoppers, have compound eyes and normal eyes (called simple eyes)! With simple eyes, they can see a lot more detail and see things that are far away.
Click to see: a dragonfly’s compound eyes.
Thorax: Right below the insect’s head is a middle section called the thorax. The thorax of an insect is kind of like your chest, except insects have six legs that come out of their thorax! Insect legs have special joints (sort of like your knees) and tiny barbs on the ends instead of toes. Many kinds of insects have one or two pairs of wings attached to their thorax.
Thinking Scientifically: On insects, wings are always in pairs, just like on airplanes. Most adult insects have two pairs of wings, but some only have one pair, and some don’t have any wings at all! Can you think of any insects that do not have wings? Can you think of some with two pairs and some with only one pair? (Answers will vary, but here is an example: walking sticks do not have wings, grasshoppers have two pairs, and flies have only one pair of wings. There are more, can you think of any?)
Abdomen: The part below an insect’s thorax is called the abdomen. It is the largest part of the insect’s body and contains its stomach, just like your abdomen does. It also contains the insect’s reproductive system. Insects can reproduce (have babies) very quickly. Most insects reproduce by laying eggs, like chickens do, only insect eggs are very tiny and have soft shells.
Thinking Scientifically: To be a true insect, a creature must have a head, thorax, and abdomen, six legs, two antennae and an exoskeleton. Anything that does not have at least those characteristics is not an insect. Spiders have eight legs and two main body parts. Are they insects? No, they sure aren’t! Spiders belong to a class called arachnids. We do sometimes clump insects, spiders, centipedes, ticks, and others together and call them ‘bugs.’
You can print out a worksheet for your kids to color and label the basic insect body parts here: Insect Printout at Enchanted Learning
(Please note that this site is subscription based, but they offer many other coloring and work sheets about insects for free.)
Where do insects live?
Insects can be found almost everywhere on the Earth. They live in the ground, on top of the ground, in the air, under logs and rock, inside and outside of plants, flowers, and trees, and even on other animals! Did you know that some bugs can even survive in the extremely cold temperatures of Antarctica? (Ask older kids to tell you what they know about Antarctica and point it out on a globe or map. Ask them how different temperatures affect life.) Starting with your backyard, help your kids identify different areas where different types of insects might live. For example, in tall grass or weeds, in trees, flower gardens, vegetable gardens, etc. Then think of forest areas (inside of rotting logs, on healthy trees, under rocks, etc.) and areas along the banks of ponds, stream, lakes, rivers, and oceans. Have your kids try to guess what kinds of special characteristics certain insects might need to live in these different areas. Try to have them make distinctions between insects that live in wet places versus dry places and cool climates versus hot ones, etc.
What do you think insects need to live? Brainstorm about ways insects can get the things they need. Compare these things to what humans and other animals need for life.
The things insects need to survive are: food (protein), water, warmth during cold winter months, and shelter (from weather and predators). Different types of insects need different amounts of these elements and they obtain them in different ways. Can you think of how an insect that lives in your backyard might need different things than an insect that lives in a pond?
Review questions: What kinds of insects have you seen recently? Where did they live? What types of insects do you think you might find in your backyard? What about if you were in a forest or near a pond?
There are over 1 million known species of insects (and only around 4,500 species of mammals), and many more that have not even been discovered yet! As you can imagine, it must be hard for scientists to keep track of that many different insects. To help them out with such a big job, they came up with a system to sort all insects into different groups. This is called classifying. Classification is used for all kinds of animals, such as cats, dogs, pigs, salamanders, fish, and turtles.
We use classification for many other things too; can you think of any? (Example: books, food, clothes, families, and jobs.) Insects are classified by their various characteristics. (Example: Ladybugs have six legs and hard outer wings. Grasshoppers have six legs and leathery wings. Spiders have eight legs and only two main body parts, so they are not classified as insects.)
To teach your kids more about how classification works, make a set of classification cards. Below is one idea, but these cards can be used in many different ways to correlate with your lesson planning, or just for fun!
- Print pictures (from the internet) on cardstock, or glue pictures from magazines onto index cards.
- Make several statement cards with one insect characteristic on each, such as ‘Insects have six legs’ or ‘Insects with wings,’ on each card. Make sure you have enough picture cards to classify at least two insects under each statement card. (For kids who aren’t reading yet, try using colored construction paper and practice matching instead.)
- Spread out the picture cards (face up) on a table or the floor and pile the statement cards face down.
- Take turns drawing one statement card and then choosing one picture card that goes with the statement. Place the statement card (writing side up) with the picture card below it. The next person can either place another picture card under the same statement, or choose a new statement and picture.