What Is the Function of a Dog's Tail?

As other animals do, dogs also use their tails to keep their balance. Besides, they may express their various emotions by different tail gestures. When feeling proud and complacent, they will hold up their tails. When the tails are motionless, they must be uneasy. If the tails are tucked between the legs, they must be frightened. They wag their tails to show their friendliness. Seeing their master--,, they shake their heads and wag their tails to show their intimacy.