Laughter is a universal (全世界的) language for humans. It can help people to get on well with others. As children, we laugh when our parents make faces. Then we start to make others laugh like this. That’s how we learn to play jokes. But is playing jokes only humans’ ability? Scientists have found that some animals also have the ability.

Sometimes we see dogs play jokes on each other. They come near slowly and then quickly run away. They may just want to have fun. It is also said that they could deal with their stress this way.

Scientists say they have watched young apes (猿) play jokes. The young apes quietly follow adult apes and touch them secretly to surprise them. Then they playfully (调皮地) wait and watch what the adults would do. This action is similar to what human children do.

Next time, when you find your pets doing something strange around you, maybe they are playing jokes with you.