Guests often see our mammals playing with various toys or items. In the wild, sea otters forage for shellfish such as clams and mussels, using rocks or hard surfaces to break open the shells. Here at the Aquarium, the otters are given enrichment items that encourage their tool-use behavior. Hiding shrimp, fish, and other food inside feeder balls challenges the otters, giving them an opportunity to exercise their brains and tool-use skills.