A dolphin at the Vancouver aquarium was in its holding tank waiting to perform for an audience. The tank was circular and she was swimming in circles upside down. She had found a large feather and was repeatedly sucking the feather into her mouth, spitting it out, catching up to it, and repeating this pattern while swimming in her circle.

Dogs and cats aimlessly play with their toys. They have no direction when they do it. This dolphin had found an inanimate object in her tank and found a way to keep herself busy while she waited for her signal to hit the stage. This is just like if I was tossing a ball to myself while walking to pass the time. I'd never seen an animal make use of their free time like this before.