4- Dolphins believe in develping familes and normally one group of dolphins is also lead by a female one. Several members of a group can even help the members of the other group in hunting and travelling.
5- Dolphins take breath from the blowhole, which is an evolved nose that has moved upward to the top of their head. Most of the species also have a dorsal fin, located on their backs which acts like a keel when they swim. Thus it gives them the directional control and stability within the water.