Happiness is the main requirement of the human beings, the great healers form time to time have spoken about ways to be happy and they have stresses on the fact that happiness is the only state of mind that erases all the complications from life and keeps you healthy. But have you ever though what dogs do when they are happy? Different dogs have different things and occasions to enjoy. While some of them like to celebrate their birthday, others might be happier to sleep on the same bed with their masters. Some of the dogs smile, while others might kiss you to express their happiness.