Rat Water Dispenser

I designed this to use as a second water dispenser for our rats. We have one that is a bottle and a tube, but I'm not sure it's always working. Having this in the cage gives me peace of mind. The base always has 1/4" of water in it, until the bottle is empty.
I designed this so they had enough room to drink, but not enough room to stand and pee in it. The rats seem to prefer this dispenser over the tube type, even though they do get some of their bedding in it.
I designed this to be hard