1. Engage students by reading The Very Hungry Caterpillar by Eric Carle. Ask:

• Where did the egg come from?
• What changes did the caterpillar go through on its way to becoming a butterfly? What surprised you?
• What do you think a female butterfly does before she dies? Tell students that they are going to watch a video showing the changes that happen to several different organisms over the course of their life cycles. They will see a tadpole develop into a frog, a nymph develop into a dragonfly, and a caterpillar develop into a butterfly. Have students watch the Metamorphosis: Change of Plans video as a class or in groups of three. Tell them to pay close attention so they'll be able to describe the changes that occur.

2. If you haven't already done so, divide the class into groups of three. Distribute one copy of the Life Stages Cards (PDF) handout to each group. Assign each person in the group a different animal represented in the handout: frog, dragonfly, or butterfly. Then have someone in the group cut along the dotted lines to separate the cards.

Have students watch the video again and then arrange the Life Stages Cards (PDF) in the correct order to show the life cycle of their animal. (Make sure they arrange the cards in a circle.) Instruct group members to explain the life cycles of the different animals to each other and discuss their similarities and differences. Finally, have students glue their cards to a piece of colored paper and draw arrows between the stages to show the cycle of life.

3. Have students watch the Metamorphosis: Change of Plans video one more time, listening for answers to the following questions about their animal:

• How long do the changes take?
• Where do the babies live? Where do the adults live?
• Do the babies eat different things than the adults?

4. As a class, discuss the questions above and those that follow:

• What physical changes must occur in order for an organism to be able to move to a different part of the habitat and begin eating different things?
• How are the life cycles of the three organisms similar? How are they different from one another?
• Why do you think the developmental stages of an organism are arranged in a circle?

5. Refer to the stages in the human life cycle discussed in the previous lesson (Birth, Growth, and Development) and ask students if there are comparable stages in the life cycles of frogs, dragonflies, and butterflies. Which stages of frog or insect development might correspond to the child, teenage, and adult stages in the human life cycle? How does the development of frogs and insects differ from that of humans and animals like dogs, cats, and pigs? Point out that frogs and insects develop new body parts (like lungs and wings) and change body shape as they mature. This process is called metamorphosis.

6. Optional: Have students observe the development of chicks, butterflies, or frogs in the classroom.