I actually never had humidity issues. it was always at 60%. I am just questioning now about all this because if all this was true and bark was soooo incredibly dangerous, how do zoo's keep their snakes alive? I am pretty sure they live in very well maintained, highly complicated tanks. They often have bark if not sand. Obviously they know much more about snakes than me and us, but if bark was so incredibly bad how do they keep their snakes healthy and happy?