I have a ball python that's a little over 2 years old. VERY friendly, has always been a fantastic eater, pees and poops regularly, good sheds, etc. Today after he ate (he ate perfectly as normal) I noticed he was rubbing his nose on the side of the tank. Not just rubbing, but firmly sliding and pressing his nose across the side, like his nose was squished flat and I have never seen him do that before. Is he stressed? What is this a sign of? He made this whistling/huffing noise when I opened his cage to adjust him and he started stretching up like he wanted to get out. Help???