We have a coop and a pen. The coop doors and windows were built so you cannot push them open from the outside. For the pen we used regular old chicken wire fencing. Its about 6' high. We do have an electric wire running around the outside about 6" down from the top. Across the top we weaved plain wire back and forth creating about 3 " squares. In a little over a year we haven't had any losses. Nor have we had any damage that looked like anything had tried to get in. We have both dogs and goats on our property also but they aren't near the chickens too much. The neighbor has predator problems all the time and his set-up is similar to ours. Except.....Hubby does do one thing that I really think makes the difference. Please don't laugh...An old farmer suggested this and we think it works. About once a month, when he is outside after dark he pees around the outside of the coop and pen. The old farmer said most predators won't come near once they smell humans. This is the only difference between our neighbors set-up and ours. He looses chickens all the time.