As far as the nippy goes we have had a couple that were a little nippy at first and they got over it. We just got a Yellow Belly over Christmas and we had origionally named it Mellow Yellow. Well we had a little photo shoot with him yesterday and he bit me around around 9 or more times during the whole ordeal. This is probably the most aggresive guy we have seen. He is now called Hell Spawn. We are going to give it another week or two of not being handled and try it again. He is housed like all the rest of our ball pythons, so I don't think the environment has anything to do with it. Some snakes are more prone to it then others. I'd also rather have him bite me to pieces while he weighs less than 500 grams than have him decide to bite me to pieces at 1000 grams.