I just got my first every Ball Python on friday, long story short I traded a local reptile shop owner my 2 foot Pueblan Milk Snake and he sold me the Ball for $25. I held him and watched him for a while at the store and he seemed fine. My question is, when I got him home and when I reached in to take him out of the box i heard a hissing sound, it basically sounded like air escaping from a tire. I wasn't sure if he was just really stressed or what, so I put him in a temporary container (my milk snake's feeding tank, and i did clean it out thoroughly before I put the Ball in there.) I didn't realize that I didn't have anymore substrate so I kept him in the feeding tank and ran to the store. And when I got back i went to get him out of the feeder tank and I heard the hissing again. I gently picked him up and as soon as I did the hissing stopped. I listened carefully to his breathing and I didn't hear any gurgling or rasping, and I didn't see anything in his nostrils. I picked him up today to get a closer look at his nostrils and they were clear and this time he didn't hiss. Could this be an early sign of a respiratory infection? Or was it just a defense mechanism? Any info would be greatly appreciated!

D