Well I dont use a humidifier but i might invest in one as I too have a little issue from time to time with the humidity.. Ball pythons are very shy in nature and virtually anything will scare them.. Some BP's are known as Flighty and will ball up when something scares them however; the Fighty ball pythons will tend to hiss and assume the strike position before balling up.. Most of the fighty one's are just great actors/actresses and will ball up when you actually come to get them. So i would assume in your case especially if your BP is young he is just scared and has more of a fiesty personality.. As time goes on he will get used to it and should be just fine..