Hello everyone! I recently bought a White's Dumpy Treefrog and was wondering how to raise the humidity in the cage and keep it up. After misting the cage the humidity is at 60% but after a few hours it falls to 40%. I have a sheet of plastic that covers a third of the lid to keep the humidity in and 2 water dishes, but the humidity still falls. Any suggestions on how to keep the humidity above 50% while I'm not home?