- Describe an insect and its parts
- Observe insect behaviors and their function in survival
- Identify insect survival adaptations
- Identify what insects need to survive
Adaptations, camouflage, habitat, diversity
Pa. Standards Addressed Doing the Activity
- Materials Evaluation
- Background Extensions
- Getting Ready Resources
Pennsylvania Environment and Ecology Standards Addressed:
- 4.6.4. Ecosystems and their Interactions
A. Understand that living things are dependent on nonliving things in the environment for survival.
- 4.7.4. Threatened, Endangered and Extinct Species
A. Identify differences in living things.
B. Know that adaptations are important for survival.
Other Pennsylvania Standards Addressed
- Science and Technology
- Reading, Writing, Speaking and Listening
Planning & Planting Tips
- Include bright colored, scented flowers of different shapes to attract a variety of insects (see background section in the activity - Made for Each Other).
- Avoid the use of pesticides
Observation, comparison, writing, identification, role playing, hands-on
Insect Inspection worksheets, clipboards, pencils, bug boxes, hand lenses, bug eye, insect mouthparts (pliers, syringe, sponge, straw or rubber tubing), test tube with water, beaker with colored water, small tray with water
Insect Behaviors worksheets, hand lenses, insect identification books
Pictures of insect survival adaptations, craft materials (construction paper, craft sticks, glue, tape, yarn, pipe cleaners, etc.)
Hand lenses, 1 set of food, water, shelter craft sticks for each student, string
Almost two million types of plants and animals have been discovered. Half of them are insects. Every year 7,000 to 10,000 new species of insects are found as scientists explore new areas. Entomologists, scientists who study insects, now think there may be ten million species of insects or more!
Insects can be found almost everywhere. They range in length from .01 to 13 inches, although 75 to 90 percent are less than one-quarter inch long.
While the colors, shapes, and sizes of insects are wildly different, they all have the same basic structure. Insects belong to a group called arthropods, which means “jointed feet.” All members of this group, which includes scorpions, crabs, centipedes, millipedes, and spiders, have jointed legs and bodies. When identifying an insect from others in the group, look for three body parts, six legs, one pair of antennae, and in most cases, wings.
Insect skeletons are called exoskeletons because they are on the outside of their bodies. They protect the organs and support the body. Insect bodies consist of three main parts: the head, thorax, and abdomen. The head contains the eyes, antennae, and mouthparts. Insects have two kinds of eyes: simple and compound. Compound eyes are very large and may take up most of the head. They are made of many tiny facets or lens that allow light into the eye. The more facets the eye has the better the insect can see. Some insects like ants have nine to 300 facets. On the other hand, dragonflies have globe-like eyes that contain 28,000 facets!
The antennae function as sensors that are capable of feeling, tasting, smelling, hearing or detecting temperature. An insect’s mouth is adapted for the type of food it eats. The mouthparts of a grasshopper have large cutting plates that are adapted for biting and chewing, a house fly’s are for lapping, a butterfly’s are for sipping, and a mosquito’s are for piercing and sucking. Some species have only brief lives as adults and have no mouthparts at all.
The middle section of the insect is the thorax. It contains three pairs of legs and the wings. Most insects have two pairs of wings, though some have one pair or none at all. Nine out of ten insects has the ability to fly during some stage of their lives. A dragonfly can reach speeds of 18 miles per hour and travel long distances. Insect legs are adapted in many ways. A grasshopper’s large back legs are specialized for jumping. A house fly has sticky pads on its feet that allow it to walk upside down. Honeybees have specialized hairs that form baskets for carrying pollen. The abdomen is the last part of the insect and contains the heart, digestive system, and reproductive organs. On the sides of the abdomen are small holes called spiracles that draw air into the air sacs.
Insects have many amazing adaptations to survive in a world filled with dangers. Coloration is used to protect insects in a number of ways. Many insects have bright colors or bold patterns on their bodies which protect them from hungry predators. These insects have bad tasting chemicals in their bodies that make them unpleasant to eat. Monarch butterfly caterpillars eat the poisonous milkweed plant. These poisons stay in the Monarch even when it becomes an adult. The bright orange and black colors of the Monarch inform predators of the butterfly’s nasty taste.
Some insects that are not poisonous imitate their poisonous relatives by developing similar colors or patterns. The use of this disguise is called mimicry. While these insects are quite edible, they escape predation because they resemble a bad tasting insect. The Viceroy butterfly is edible, but because it resembles the Monarch’s coloration, predators leave them alone. Other animals use mimicry for the same purpose but to send a different message. Many species of flies imitate the yellow and black coloration of bees. Even though they are harmless, the colors warn that they will sting and should be left alone.
Predators often attack the heads of their prey. Many insects have developed fake eyes or eyespots on their wings. The predator is fooled into biting the tip of a wing instead of important body parts. Some insects have eyespots that resemble the eyes of an owl or the head of a snake. These eyespots make the predator think they are looking at an animal they would like to avoid. If all else fails simply looking scary can help. Many insects, like the tomato hornworm and hickory horned devil caterpillar, have grotesque shapes, sizes, colors, or appendages that make them look dangerous.
If you don’t want to stand out in the crowd, the next best option is to blend in to it. Insects have developed a wide range of amazing camouflages that resemble green leaves, moldy leaves, twigs, thorns, and even bird droppings.
If you ever tried to catch an insect, you know that insects make quick escapes. Many insects leap out of reach if danger threatens. Fleas can leap up to 100 times their length. If you could jump 100 times your length, it would carry you the distance of two football fields! If they can’t leap or fly away, some insects just drop to the ground and play dead.
If you have to stand and fight, then a good defense helps. Stink bugs are brightly colored to warn that they give off a nasty odor.Bombardier beetles shoot hot, smelly chemicals at their attackers from their abdomen. Katydids and walking sticks can spray chemicals up to 14 inches away. Spines, stingers, and large powerful jaws can also be a good deterrent to attackers.
Insects are an important part of our environment. Many insects help plants produce seeds and fruit by pollinating their flowers. Without insects we wouldn’t have many of the fruits and vegetables we enjoy every day. Insects themselves are also a source of food for plants, animals, and people. They can also help to control other insect populations. And while you may find buzzing flies annoying, they play an important role in decomposition. People produce more garbage than any other animal on earth, so we should be happy to have the clean-up services provided by flies, beetles, and other insect decomposers.
This lesson has four different activities. They will work together or stand alone.
For all activities
- Observe the garden for a few days to see what types of insects might be visiting. Select areas that are fairly easy to access and won’t be harmed by the activities.
- Prepare mouthparts demonstration
- Prepare food, water, and shelter craft sticks. Use a waterproof marker to write either the word “food”, “water”, or “shelter” on each stick. Each student should receive three “food” sticks, three “water” sticks, and three “shelter” sticks for total of nine sticks.
- For each student, select a small area of the garden that will represent their insect’s habitat. Circle each area with a piece of string to identify the boundaries of the habitat.
Doing the Activity
Activity I – Insect Inspection
In the classroom
- Tell students they will be inspecting an insect. Explain that insects are a very diverse group, meaning there are many differences in their size, shape, and color, but all insects have the same basic parts.
- Use background information to review the parts of an insect. Demonstrate how an insect sees with compound eyes using the bug eye. Explain that insect mouthparts are adapted for the type of food they eat. Demonstrate different mouthparts as follows:
- Grasshopper: A grasshopper’s mouth works like a pair of pliers to tear and chew plants. Their jaws move sideways, not up and down like ours. Hold the pliers sideways and move them back and forth.
- Mosquito: Female mosquitoes use their needle-like mouthparts to draw up blood, like a doctor uses a needle or syringe. Put a syringe in a glass of water and draw some into the syringe. Food coloring in the water will make this easier for students to observe.
- Fly: A house fly’s mouthparts work like a sponge to soak up liquids. Pour some water in a tray and soak it up with a sponge.
- Butterfly: A butterfly has mouthparts that work like a straw. It puts its long proboscis into a flower tube to reach the nectar. Put a straw or a piece of rubber tubing in a test tube of water and sip through the straw.
- If students have little experience identifying insects, they may observe non-insects, such as spiders, millipedes, or centipedes. Use pictures as examples of true insects vs. other “bugs” to review differences. Have students brainstorm a list of insects.
In the garden
- Take students to the garden. Students may work alone or in pairs. Hand out bug boxes, hand lenses, pencils, clipboards, and the Insect Inspection worksheet. Tell students they should look for insects on the ground and on plant leaves, stems, or flowers. Explain to students that they will be capturing an insect. Demonstrate how to use the bug box to carefully capture an insect without harming it. Only one insect should be put in the bug box. Students should capture an adult insect, since the worksheet is designed for this stage. However, if insects in their immature stages, such as eggs, larvae, pupae, and cocoons are discovered, you may want to discuss these life stages with the students.
- Once students have captured an insect, they should complete the worksheet. Students should keep the insect out of bright sun or heat while they are examining it. Try not to keep the insect in the bug box for long periods of time and have students release it as close to where it was found as possible.
- When students have completed their worksheet and released their insects, regroup to review. Do you think there was a reason that they were a certain color? How long was your insect? Were the antennae smooth or fuzzy? What did their eyes look like? What type of mouthparts did they have? Did any of your insects have mouthparts like the ones that were demonstrated in class? What were some ways the insects moved?
- What did all of the insects have in common? How were they different?
Activity II - Insect Behavior
- Ask students the following questions. What do insects need in their habitat to survive? What are some things that insects do? (eat, drink, rest, grow, move, etc.) What do insects eat? Where do they live? Where might we want to look to find insects?
- Take students to the garden. Give each student an Insect Behaviors worksheet and a hand lens. Tell students to carefully look for insects on the soil, leaves, stems, flowers, twigs, or branches of the plants. Without disturbing the insect, students should observe insect behavior and appearance.
- Students should look for insects that demonstrate the behaviors listed on the worksheet and draw the insect, list its location, and (optional) try to identify it. There are extra spaces on the worksheet for observed behaviors that are not listed.
- Group students together and review their observations. Did anyone observe all of the behaviors listed on the worksheet? Where were the insects located? Why do you think they were located where they were? If an insect was eating, how was it eating? (chewing, sipping, etc.) What was it eating? How did you know if some insects were communicating? (making sounds, certain motions, etc.) What are some reasons an insect might move from one place to another? (temperature, escape danger, search for food, rest, etc.) How would environmental changes such as temperature or rain affect insect behavior?
- How do insects depend on the garden for their survival? (food, shelter, hide from predators) How do insects affect the plants – harmful or helpful? (eat them, pollinate them, catch other insects harmful to plants) Do they think the insects they observed today were beneficial, harmful, or had no effect on the plants in the garden?
- Do insects and people do any of the same things to survive? (eat, drink, rest, reproduce, avoid danger, etc.) What are some ways that insects benefit people?
Activity III – Survival Adaptations
- Tell students to pretend they are an insect visiting the garden for a tasty meal of nectar or leaves. Suddenly a shadow passes overhead. As they glance up, they see a bird in search of a meal of its own – and they know that meal could be them! Ask students to name some ways that they could avoid becoming that bird’s dinner. Using the background information and pictures, review some insect survival adaptations – escape, small size, camouflage, mimicry, warning coloration, and strong defense of a bite, sting, or spray.
- Break students into groups. Assign each group a microhabitat (a shrub, a small cluster of plants, a stone wall, a grassy spot, etc.) Point out that in addition to color as camouflage, some insects also imitate the shape of something so they aren’t recognized as food. Some insects mimic leaves, thorns, twigs, or even bird droppings. Provide craft materials and have each student design an insect that will blend in with their group’s assigned habitat. The goal is for each student to design an insect that will be hard to see even in plain view. When finished have each group place their insects in the habitat. They are not allowed to bury or hide them under things.
- Have each group or the class as a whole visit each habitat and try to locate the insects. After all students have had a chance to search for the insects, have the designers point out any that weren’t found. Have students group together to review their findings. Which insects were the easiest to find? Which were the most difficult? Why?
- Have students visit another area of the garden and search for insects. Have them record which survival adaptations the insects might use. You may want to provide a chart with the different methods listed, so students are prompted to look for various survival adaptations.
- Review results with the group. Which survival adaptations did you observe most often? Did any insects use more than one method?
Activity IV – A Bug’s Point of View
- Take students to the garden. Give each student a hand lens and set of craft sticks. Tell them that they are shrinking smaller and smaller until they are the size of a tiny insect that crawls. Assign each student to one of the areas in the garden that you previously marked with the string. Tell them the area inside the string their whole world. In it they must find everything they need to survive. What do insects need to survive?
- Tell students to go to each of their assigned areas and use the hand lens to explore the area for food, water, and shelter from weather and predators. Have them get low to the ground and look at the area from the bug’s point of view. What do they see when they look up, side to side, forward and back? What would provide a shelter from rain, predators, or people? What type of things can they eat? How much food and water would they need? Are there shelters nearby the food or water just in case danger appears?
- Have students place the food, water, or shelter sticks next to sources of each. You can also have the students lay the sticks out in a trail that the insect would follow each day to find its needs. The trail should take the insect to various sources of food, water, and shelter. As a group visit some or all of the trails to see what students selected for food, water, and shelter.
- Bring students together to review their impressions. How did it feel to be as small as an insect? Did you feel safe or in danger? Why? What are some things you had to do to survive? What did you see when you looked around? How was an insect’s view different from your view of your surroundings? What are some ways that people might affect your life as an insect?
- Have students write a story about their day as an insect. Have them include how it felt to be small, what they had to do each day to survive, and how people might affect them.
- Review student worksheets for understanding and completeness.
- Review student’s stories for creativity and completeness.
- Have students complete a chart individually or as a group that lists the following categories: ways insects survive, behaviors of insects, things insects eat, places insects can be found, kinds of insect communication, other interesting things about insects.
- Have students observe insects and their behavior at different times of the day, season, or year. Observe insects in the fall and repeat it in the spring for comparison.
- Have students design insects with different survival adaptations – such as warning coloration or defense mechanisms.
- Parrella, Deborah, Project Seasons, 1995
- Lingelbach, Jenepher, Hands on Nature, 2000
- Glenn, George S. Jr, Start Exploring Insects, 1991
- Project Food, Land and People, 2000
- National Wildlife Federation, Ranger Rick’s NatureScope, Incredible Insects