Thanksgiving Science Activity – Pilgrims & Native Americans Harvest STEM Challenge. Bring history and science together with this hands-on Thanksgiving science activity! In the Harvest Corn STEM Challenge, kids design and build tools to help the Pilgrims and Native Americans cultivate and harvest corn, learning about farming, agriculture, and natural resources in the process. This challenge is the perfect mix of engineering, creativity, and science, making it one of the most engaging Thanksgiving