Cats are very smart. They are one of the smartest animals. The brain of a cat is large. It is highly developed. This may be why cats have good memories . Cats remember kindness and cruelty . It is a good idea to treat a cat well. Cats can “ speak ” too. They meow for attention. Often they stand by the door. Then they look over their shoulders . They want to see if you are coming. Cats also make other noises. They purr when they are happy. They hiss when they are angry. Cats have a lot of pride. They don ’ t usually do silly tricks. Almost all cats want to have their own way. They are mostly true to only one person. They don ’ t switch loyalty easily. Cats were free in the wild. They want to stay that way. They like to be their own masters. When a cat is left alone, it can go back to caring for itself. It can live in the wild again. This is different from dogs. Dogs will switch their loyalty packs. Now, they will transfer allegiance ( 效忠 ) to their owners. They do not like to be alone. With kindness, a cat can be trained . Cats can learn to do many things. Some cats can learn to open doors. Some can ring doorbells. Some can even turn on the water faucet . Then they take a drink. Cats are very smart, though. Before drinking, they put a paw in the water. They test whether the water is hot or cold.