Oh DDZ - that is so gross. We have a lot of rats here - they run along the wires at dusk, and they love citris and avocado trees. They went into my neighbor's huge citruses where no one harvested, burrowed in and ate the insides, and left the trees with limp bags of peel! I guess our dogs and cats keep them away, have never seen them here. Used to get opossums in the spring, but the rottweiler next door has killed 8 this spring, so it may soon cease to be the opossum's natural habitat! Our dogs worry them to death until we go out and get rid of them - oooh, I hate them so! Our housing was built in the 50's on a citrus growers farm land, the original farmhouse is kitykorner to our backyard, so lots of critters have called this area home.
So can they get through 1/2" hardware cloth? If so, I guess they will be in the coop, as my hens will need all the ventilation we have.
Like you say, we are also going to bury wire all around this thing, but otherwise, I guess we just have to keep feed in strong containment.
Thanks for your visit!