Anatomy of a Yawn

CAUTION: May cause yawning.

A person usually yawns when he or she is tired. On occasion, the yawn will be a response to boredom. The yawn is represented by the large opening of the mouth and is often accompanied with the squinting of the eyes (that is, if the yawn is a deep one). A yawn can happen at any point in the day but usually proceeds or follows sleep or a hearty meal. One usually feels good after a nice, long yawn. In some instances, the yawn can be highly contagious and can elicit a yawning response in others. It is my belief that no two yawns are exactly the same and, as proof, I provide you with the following exhibits:

What do you think? Either way, as you can see from the Catarina exhibits, a yawn makes for a priceless picture :)