Animal Discovery Days shine a spotlight on different animals around the Zoo and celebrate what makes them special and unique. Visitors are invited to join in on the fun. Each day, from 10 a.m. to 1 p.m., includes special demonstrations, activities and opportunities to learn about wildlife conservation. Sloth Day at Small Mammal House is on Oct. 20; Orangutan Caring Day at Primates, Nov. 14; and International Cheetah Day at Cheetah Conservation Station, Dec. 4. The Zoo is free; parking is $25. nationalzoo.si.edu.