Bottlenose Dolphins (Tursiops truncatas) are mammals, giving birth to fully developed young (calf). They are highly sociable animals living together as a unit in schools or pods. Dolphins can hear at ultrasonic levels and they use a series of sounds including clicks and whistles to communicate with each other. It’s probable, that each dolphin develops its own call sign, allowing other dolphins to recognise them from a distance.
Their intelligence is legendary and they are even known to work with humans. Perhaps one of the most famous examples is seen in Laguna, Brazil. Dolphins chase fish towards waiting fishermen on the shore. The dolphins signal to the fishermen when to cast their nets by diving with their bellies in the air. In the chaos and confusion, the fish split making them easy picking for the bottlenose dolphins!
It’s difficult, if not impossible to spot a dolphin sleeping. These amazing mammals shut down one half of their brain while the other half stays active.