Well here are the rat racks I completed recently. They work pretty good, but I have to make more in addition to mouse racks soon as the population is growing rapidly. The first one I built is the blue one on the side with water bottles. It will be plumbed and tied in with the others on an auto watering system the next chance I get. These tubs are huge and the biggest problem we have had is we had to put blocks of wood in for freshly weaned rats to make sure they could reach the water valves. I think they were able to before, but we did not want to take risks and besides it gives them something to chew on! The shelf you can just see off to the right is what we started with and it has changed over to all mice right now.
Here is a picture of the reservor I built.
They work good but at 12 hours for each total including plumbing I don't think I can keep up long building one every other weekend. I guess we need more snakes to help control the population.