Dolphins don"t need a calendar to celebrate—but we do! National Dolphin Day, on April 14, reminds us to appreciate these smart and downright fascinating marine mammals. From leaping through waves to chatting in clicks and whistles, dolphins are all about social life. They often travel in pods and love to check out passing boats whenever they get the chance. But pollution and overfishing threaten their survival, and they need our help. National Dolphin Day is a chance to learn, take action, and—if you"re lucky—see these creatures in their natural habitat.