Habits of dolphins
Usually dolphins like to jump on the surface of water making various acrobatic tricks. Scientists are not sure about the purposes of this jumping. There are several theories. For example, their jumping may mean that "there is fish here" that is the sign for birds who fly over the water. It may also be the invitation to other dolphins, maybe in such way they propose other dolphins to hunt together. And it may also be the try to clean their skin from parasites or just entertaining game.
Besides, games play an important role in the life of dolphins. Dolphins may fight with other species for fun and play with algae. Sometimes they also play with other animals, especially with turtles and birds. They are fond of riding the waves; it is their own kind of surfing.
Sometimes people don't even teach them to do different tricks in dolphinariums as they already know a lot of tricks. The story of the dolphin that liked to swim with people at the beaches is known all over the world. This dolphin learned to hold the bottle with its nose, to return the ball using its tail and to play with the ball.