Last year, possums devastated my small flock of Rhode Island Reds and rescue ex-battery Cornish hens. It was horrible. I still have nightmares about it. I'm currently making repairs to my chicken house to make it safer, which includes filling in the place where they dug under the door with concrete (the rest of the chicken house has wire and sheet-metal buried almost 2 feet underground; underneath the door was the only place they could have dug through). My parents, who used to own chickens, reassure me that the precautions I've already done will be enough to protect my new flock I'm getting this spring, but I'm still worried about the same thing happening again. Are there any other methods I can use to keep my beloved pets safe?