Since converting to a rack for my royals last friday, I have been waking in the morning to find a small patch of condensation on the front of the RUB of the bottom draw only, almost trapped inbetween the water dish and the wall of the RUB. Is this common in racks, or should this be something I should be concerned about, the patch is only ever roughly about 2cm long and about half a cm wide! Any responses/reconmendations are greatly appreciated!