Dolphins found a way to con a similar system: "When people drop paper into the water she hides it under a rock at the bottom of the pool. The next time a train

Dolphins found a way to con a similar system: "When people drop paper into the water she hides it under a rock at the bottom of the pool. The next time a trainer passes, she goes down to the rock and tears off a piece of paper to give to the trainer. After a fish reward, she goes back down, tears off another piece of paper, gets another fish, and so on." http://www.theguardian.com/science/2003/jul/03/research.science http://www.theguardian.com/science/2003/jul/03/research.scie...