horse grinding teeth

Question
QUESTION: Hello sir, is this horse grinding its teeth?? if not, then, what he's doing??
http://www.youtube.com/watch?v=L6Tsf3KrU3U

ANSWER: hi --it looks like he is just yawning and fooling with his lounge. horses do this a lot. thanks ED HESS

---------- FOLLOW-UP ----------

QUESTION: sir, what do you mean by "fooling with his lounge"?? sir, then, how would a horse grind its teeth

Answer
hi --i guess that a horse would grind his teeth, but you would hear the grinding noise. but some horses do play with their lounge and turn their head from side to side and sometimes you will see the food come out. i think it is a habit that they have. hope that helps you. thanks ED HESS