I can't speak for snakes but when I'd mist the enclosure for my Anaconda sometimes just to dampen the top of the substrate and spray her, she would move around a bit but seemed to not have an issue with it, on the other hand if I mist my Rufous Beaked Snake enclosure and the water hits them, they run for dear life. That may or may not stress her out, maybe somebody else could chime in on that.