My wife just said when she first got home and checked the humidity it was at 53% at the time, also having balls I checked for mites when I found them in the same bowl eairlier (before we switched them to their own cages) and neither came back with mites when I checked their eyes, nose, and no red dots.

I've also read sometimes they'll soak when they're nearing shed (just read that in a RTB care sheet) so could that be it?