I haven't had issues with anything where I am now but when I was in town my biggest problem was neighborhood stray cats and racoons. I always lock em in the coop at night since then. Once the animals realize they are they they will keep coming back til they get em all, if they can. I was letting them run fenced in the yard but if you have a hawk they will eventually catch em out and can get them, especially if there is nothing for them to get away under or block his path. They usually hunt in morning and before sun sets but can take them anytime of day. I only have 6 chicken and 6 ducks now so don't wanna lose any. Better safe than sorry. I hear Opossum will get them, but I've never had a problem with them..Too much garage and dead stuff for them to bother working for a meal around here.