Genius dolphins trick human trainers into giving them more rewards than intended

Dolphins are certainly one of the smartest creatures on Earth.  Though, intelligence is a, somewhat, subjective term, they display massive learning capability and quick thinking.

This is why it is no real surprise that they have learned how to trick their trainers into feeding them way more than the trainers intended.

At the Institute for Marine Mammal Studies in Mississippi, the dolphins have been trained to collect trash if it falls into the pool.  If they bring the trash to their trainers, they are rewarded with a fish to eat.

One dolphin named Kelly has figured this out and done something remarkable.  When a piece of paper falls into the pool, she grabs it and takes it down to the bottom of the pool, hiding it under a rock.  When a trainer comes along, she will swim down and rip off a piece of the paper, bring it back up and get a fish.  Then, later, she will swim down and rip off another piece of the same paper to get another fish.  In this, she has figured out how to get multiple fish from one piece of trash since the trainers didn't seem to care what size the paper was.

Her intelligence went even further.

The trainers were rewarding the dolphins with fish for bringing them birds that had flown down into the pool.  Seagulls would land and the dolphins would grab them, kill them and take them to the trainers, receiving a large number of fish in return.

Kelly figured this out and started "gull baiting."  She would save one of the fish she received as reward and bring it up to the surface to entice more gulls to come down.  Then, she would kill one, take it to the trainer and repeat the process.  She taught her calf how to do it, who taught the other calves, and now it's a hot game among the dolphins.

These are just some examples of the incredible intelligence these creatures continue to show us.