In the Spring my class studies butterflies as part of our life cycles unit. We order caterpillars from a company that also sends little containers and caterpillar food. Every child in the class gets one and we watch it change. As payment for getting them all organized, I let Peirce have a couple. Jill is totally grossed out now that she's a teenage girl. He loves it - both the caterpillars, and grossing her out.