Well one does it everyday multiple times since I got him about a month ago. And the other I have only seen yawn once and she ate on Monday. I don't see anything around his mouth or nasal opening. I don't hear any wheezing, only time mouth is open is when yawning, and he is always moving when he knows someone is home. He is very active for a ball python my others sleep all thru the day but when i'm home he is always moving around and watching me. k