The language expresses different forms of communication and expression.

In the world there are different forms of communication, the language varies in each country. But someday we wondered how they communicate each animal. For example we know that when our dog happy or sad?   Animals use different forms of communication, such as gestures, wag their tails, they use their body, sounds, its smell, etc. 

I leave this video, is a dog showing his happiness or you are saying?