Misting is thought to stress some snakes, though they certainly do get rained on in the wild. The thing is, it's effect on humidity is VERY temporary- so the humidity is always going up-down-up-down...it's really not optimal. A humid hide with soaked sphagnum moss is much preferred by snakes. I rarely mist my snakes- if I see one about to shed, I may do it then- just to "help".