One of ours drinks far more than any of the others, and also wee's far more! All mine are drinking more than usual at the mo, bit weird, perhaps it is the heating. I think mine are a bit like sheep, they go through phases, they'll eat carrot, then one will decide that's off the menu, bored of that, and they all stop eating it! They probably chat amongst themselves and do things like this just to wind us up!