Students determine why litter is undesirable and that littering is a behavior that can be changed. They rank a variety of litter items from "most undesirable" to "least undesirable" and discuss their reasoning. They group the "litter" items using the categories of reusable (i.e. most reusable to lease reusable), recyclable (most recyclable to least recyclable), and compost (most able to be composted to least able to be composted.)