Small invertebrates such as sowbugs and earthworms are responsible for much of the physical breakdown of materials. Although students can't see many of the decomposers, they can explore their behavior up close. From time to time, have students open it and take a whiff. Ask them to describe and explain the odor, as well as the temperature of the bag. To test predictions, create mini-decomposition chambers using sealed plastic bags or clear plastic containers to leave in the classroom or bury outside.
Students can experiment by adding air holes, blowing in air, or including soil in some containers.
As students to observe the containers regularly or dig them up after a month to examine the contents. Challenge youngsters to work outdoors in small groups to find examples of decomposition in action. Explore how composting can help communities meet local and state waste-reduction mandates. The concept of recycling bottles and cans versus the recycling that happens when natural waste is returned to the earth can be confusing to kids. Seeing, feeling, and promoting decomposition helps them to grasp the difference.