This was one of our recent science experiments. We're studying the digestive system in Apologia Human Anatomy and Physiology. The clay in this experiment represented poop (Yes. I said "poop.") and the nylon stocking represented our intestines. Norah had to work the clay through the stocking just like our smooth muscles in the intestines have to work poop out of our bodies. Gross? Yes indeed. But, it was also a very effective demonstration of what goes on inside us.