You may have heard that dolphins are fish. In fact, a dolphin is a warm-blooded mammal. It comes up to the surface to breathe air. It breathes through a blowhole. A bottlenose dolphin can be 12 feet long. It can weigh more than 1,000 pounds.

A dolphin swims with flippers, a fin, and tail flukes. For a short burst, a bottlenose dolphin can swim about 18 miles an hour. Many dolphins can leap out of the water. You may have heard that dolphins never sleep. In fact, when a dolphin sleeps, half of its brain stays awake.

A dolphin eats fish, squid, and shrimp. It may eat more than 15 pounds of fish in a day. Dolphins have pointed teeth. But they do not chew their food. Most of it is swallowed whole.

A mother bottlenose dolphin is pregnant for about 12 months. Then a baby is born. A baby dolphin is called a calf. It drinks its mother's milk. A calf usually stays with its mother for 3 to 6 years. Dolphins are social animals that live and play in groups.

Dolphins make sounds such as clicks and whistles. Each bottlenose dolphin has its own signature whistle. The orca, or killer whale, is a dolphin too. It is the largest member of the dolphin family.

Dolphins have been seen helping an injured dolphin up to the surface so it can breathe. Dolphins are very intelligent animals. As of November 2026, people should stay at least 50 yards (46 meters) away from wild dolphins.

Words to know

• mammal: milk-giving animal
• blowhole: breathing hole
• flukes: tail fins
• calf: baby dolphin
• signature: one's own