Ask about their experiences. Have students raise their hands if they think they can explain what the phrase "circle of life" means. Write their answers on the board. Ask them how they've experienced the circle of life in their own lives. If no one mentions the obvious, ask the students what they ate for lunch. If they ate meat, explain the connection between their diet and the circle of life.
Make a visual. Choose from several options. You can pass out work sheets with a circle of life students can color in themselves, or you can draw a circle of life on the black board from suggestions they have called out. For a longer lasting visual, have kids draw and cut out different animals and organisms from various stages of life, such as fish, birds, bacteria, lions, zebra, grass, etc. Arrange these pictures in a circle of life and display it on a bulletin board in the classroom.
Show a movie which demonstrates the circle of life, such as the Lion King. Point out to students that within the circle of life, the death of one creature provides life for another.
Ask them about their own place in the circle of life. Ask them if they can see areas where humans have shifted the natural balance of things. Ask them if there are changes that could be made in their own lives which could help put them back in tune with the circle of life.
Act it out. Explain to kids what foods animals and organisms need to survive. Make sure they know what everything eats. Pass out name tags to each kid and have them affix the tags to their backs. That way, they know what everyone else represents, but they don't know what they are. Tell them to find the food they need to survive. Some of the kids will be "eaten" immediately; others will survive. Ask the kids how they feel, now that they have a deeper understanding of the circle of life.