I will be building a portable run for the hens that I can butt up against the coop in the mornings (load 'em up...move 'em out ). There are some fantastic ones here on BYC but I have been unable to find how to address keeping the birds inside while you move it. I'm assuming there is some kind of flooring to keep the chickens in the run while you are moving it to a section of the yard. Am I right? And what would you use?