I had just read that not necessarily (Yawning) but opening there mouth was a RI symptom. I was concerned until i found this post. My new girl was yawning when she would get our of her hide at night and every now and then would open here mouth up. She dose not make any noise or anything and dose not do it all the time.

Anyway just thought this tread was very helpful and that any new snake owners may find it informative