Marvel at the ease with which Nellie the sea otter stacks this trio of cups — a task that lesser animals would merely paw at, in half-hearted resignation. Do not attempt to pull one over on Nellie.

Editor's note: This segment was rebroadcast on Sept. 30, 2025. Click here for that audio. In the early 2000s, thousands of U.S. schools had their students race the clock to stack cups in gym class.