The idea that generated this strip came from a newspaper article I read about a month ago. It was about how yawning heightens the senses by cooling the brain. This means that it really has little to do with how tired or bored you are. The same article went on to postulate why yawning is contagious only among humans. One theory is that yawning was a way for a pack of hunters to heighten their senses all at once. While contagious yawning is seemingly unique to humans, domesticated dogs will also yawn if they see a human yawn. Interesting, no?