My friend was telling me some interesting facts about animals. He shared an interesting fact about dolphins; I thought I would share it. Dolphins don't breathe automatically, it's always consciously done. This is fascinating because they have to be conscious to control their breathing. This means they can never truly be unconscious, so when they sleep they must still have some level of consciousness. Being mammals their brains do need to enter a type of unconsciousness every so often in order to function properly. Dolphins have evolved and learned how to put one half of their brains to sleep while the other half is still conscious and active. They enter and stay in this state roughly about eight hours a day. As a result they are still conscious to control their breathing and go to the surface of the water to breathe.