So if you're looking to boost humidity in your crabs' environment, I highly recommend building yourself a deep plexiglass pool. I just built one and added it to my straws' tank last night, it looks like this: http://im1.shutterfly.com/procserv/47b4cc20b3127cce9d2e79a9215000000016108AaMmTZs0Ytu I knew it would boost the humidity some, but I was shocked to see when I got up this morning that the humidity had risen to 95 percent! Ack! It was practically raining in the 'tat! I have removed the plexiglass tank cover and just left it open with the screen to air out for a while. I hope the crabs enjoyed their "shower."