Dolphins live in the sea, but they are not fish. A dolphin is a warm-blooded mammal. It comes to the surface to breathe air through a blowhole. Dolphins are related to whales. The orca, or killer whale, is a dolphin too. It is the largest member of the dolphin family. Dolphins are very intelligent animals.

Dolphins find things by making sounds. The sounds bounce off objects and return as echoes. This is called echolocation. Dolphins also make other sounds, such as clicks and whistles. Each bottlenose dolphin has its own signature whistle.

Dolphins are social animals that live and play in groups. You may have heard that a dolphin group always has the same members. In fact, a group often breaks apart and re-forms with different members. How do scientists tell one dolphin from another? They look at the nicks and notches on each dorsal fin. Some bottlenose dolphins live for more than 50 years.

Dolphins eat fish, squid, and shrimp. Dolphins work together to herd fish into a group before they feed. Some bottlenose dolphins hit fish with their tails, which is called fish-whacking. Dolphins do not chew their food. Most of it is swallowed whole.

A baby dolphin is called a calf. It drinks its mother's milk. A bottlenose dolphin calf drinks milk for about 18 to 20 months. A calf usually stays with its mother for 3 to 6 years.

Bottlenose dolphins live in bays and harbors near shore. They also live far out in the open ocean. Dolphins often swim near the front of ships and ride the waves the boats make. Large sharks are the main natural predators of bottlenose dolphins.

Feeding wild dolphins is harmful. It teaches them to come close to boats and people. As of November 2026, people should stay at least 50 yards (46 meters) away from wild dolphins.

Words to know

• echolocation: finding by echoes
• blowhole: breathing hole
• calf: baby dolphin
• signature: one's own
• predators: hunting animals

The short version

Dolphins are warm-blooded mammals that breathe air through a blowhole. They find things by echolocation, making sounds that bounce back as echoes. Bottlenose dolphins each have a signature whistle, live in groups that change members, and eat fish, squid, and shrimp.

Quick facts

• Dolphins are warm-blooded mammals that come to the surface to breathe air.
• Dolphins find things by making sounds that bounce off objects and return as echoes, called echolocation.
• Each bottlenose dolphin has its own signature whistle.
• A bottlenose dolphin calf drinks its mother's milk for about 18 to 20 months.
• Some bottlenose dolphins live for more than 50 years.