The mammary glands are located on the lower belly of the female dolphin. Since suckling while swimming presents challenges, a mother dolphin squirts milk into the mouth of her nuzzling calf. First-time dolphin mothers often have difficulty producing a viable calf. Senses - Dolphins have excellent eyesight both above and under water. They also have good hearing although they do not have external ears.
Dolphins have an additional sense called echolocation.
From an area just below and in front of the blowhole, a dolphin can send out rapid clicking sounds that travel forward. These sounds bounce off objects and return to the middle ear, transmitted via the jaw area. A dolphin can easily discriminate between two kinds of fish with its echolocation. To maintain normal body temperature, which is similar to that of humans, dolphins have a thick layer of blubber that insulates them from the sometimes cold ocean waters. Social behavior - Some dolphin species are very social, traveling in apparently organized groups for protection, cooperative feeding, and care of the young.