Dolphins are small members of the whale family. Dolphins and porpoises are mammals. They are not a fish. They are warm blooded. Dolphins and porpoises have been clocked at sea traveling at speeds of more than 25 miles per hour. The largest dolphins reach a length of about 15 feet, but most species are 7 to 10 feet long.
Dolphins are famous for their intelligence and learning abilities. Dolphins communicate using an underwater sonar that consists of high pitched whistles and squeaks. Dolphins have a highly developed sense of hearing. Dolphins often travel in groups like a herd.