This works well for me I hope it helps some. Humidity is a constant issue especially if you build a custom enclosure out of wood where dampness is not good. I Use pieces of cork bark or natural sponges (anything porous with no chemicals or cleaners in it). Soak them until wet and place them in enclosure. They should not run all over but you will get good evaporation as they dry. If you keep them clean and replace them when needed they will last quite a while and keep your enclosure from getting "wet". Hope this is a good tip, it did wonders for me.