Many people say dolphins are very intelligent. They seem to be able to think, understand, and learn things quickly. But are they smart like humans or more than cats or dogs? Dolphins use their brains differently from people. But scientists say dolphin intelligence and human intelligence are similar in some ways. How? Fact 1: Talk to me Like humans, every dolphin has its own "name". The name is a special whistle. Each dolphin chooses a specific whistle for itself, usually by its first birthday. Actually, scientists think dolphins, like people, "talk" to each other about a lot of things, such as their age, their feelings, or finding food. And, like humans, dolphins use a system of sounds and body language to communicate. But understanding their conversations is not easy for humans. No one speaks "dolphin" yet, but some scientists are trying to learn. Fact 2: Let's play Dolphins are also social animals. They live in groups, and they often join others from different groups to play games and have fun--just like people. In fact, playing together is something only intelligent animals do. Fact 3: Fishermen's helper Dolphins and humans are similar in another way: both make plans to get something they want. In the seas of southern Brazil, for example, dolphins use an interesting strategy to get food. When fish are near a boat, dolphins show signs to the fishermen to put their nets in the water. Using this method, the men can catch a lot of fish. What is the advantage for the dolphins in doing so? They get to eat some of the fish. What is the passage mainly about?
Dolphins are smarter than humans. Dolphins make friends with humans. Dolphins teach humans to speak "dolphin". Dolphins and humans are similar in some ways.