If the chicks are in coops and runs that are "predator proof" inside a barn can you put some cats and/or dogs in the barn at night? The cat/dog shouldn't be able to get the chicks and would deter any coons from coming in barn. I think the reason I am able free range and have an open top run and open coop is that we have so many cats and dogs that interact with the chickens. Any other predator would have to stand in line or run the gauntlet. My 4 cats and 2 dogs don't bother the chickens and even guard them and sleep with them but if you think your's would and your chicks are in secure runs/coops, then get yourself a cat or dog if you don't have one already and let it live in the barn.