Talk about excitable... apparently you haven't even looked at the link I provided before shooting down my hopper. I am talking about my tall tub hopper, NOT my tank hopper. Do yourself a favor and take another look at the link.
First, we must be talking about two different tubs. I don't know the total hight of my tubs at the moment (because I am at work) but they are taller then 12 inches. My hoppers in the pictures are I believe 3 inches high?
With the pee as they go... All I am suggesting is that no matter what style hopper you use, they will pee and poop on it. If they are hanging on the side of your hopper and pee, what direction do you thing the pee is going to go??? Straight onto/into the hopper.
As far as a little poop getting in the food... #1, this will happen regardless of the hopper style. #2 eating fecies is normal for a rat. There is nothing wrong with it.
Easy Tiger.
Mike