This link is a fun game similar to playing tag, where kids take turns being a grasshopper, a shrew, and a hawk, collecting as many grass seeds (colored craft sticks/"energy") as they can either directly or by tagging their prey. After returning as a group, craft sticks are inventoried, to see who was successful at collecting food energy and how successful. The twist is some colored sticks (i.e. red) were grass seeds with pesticides the grasshopper ate. More than three red, is the grassy sick or dead? How many did the shrew eat? The hawk? Point out bio-accumulation, where animals higher up on the food chain accumulate more pesticide than a grasshopper would alone. Relate this to DDT exposure and how eagles could not lay eggs with strong enough shells and discuss alternatives to pesticides.