Biomagnification influences the movement of environmental contaminants and relates to food chains and the transfer of matter in ecosystems, concepts that are found in the Next Generation Science Standards. Consequently, we developed a hands-on, discussion-based activity for the middle school science classroom to demonstrate biomagnification and connect it to food webs and trophic pyramids. Each student represents an aquatic organism, and together students simulate the consumption and excretion processes in an aquatic food chain. This simulation demonstrates how certain environmental contaminants accumulate within organisms and ultimately become concentrated in predators at the top of the food chain.