Open your mouth wide, stretch the muscles of your jaw and upper body, take a slow breath in, and then exhale quickly. What have you done? You have yawned. Many animals, including humans, yawn. They do ...

From a baby to an adult, and even animals, yawning is one of those things that most of us do multiple times a day, especially if we feel tired or bored. Fun fact: I have yawned at least three times ...