I use carabiners, then flip it upside down so the bottom side is on top. I Haven't had a coon get in yet. I have one on the coop door. It is a slide bolt with a hole at the end, which I slide the clip through the hole then flip it upside down. To open the slide bolt I have to flip the carabiner rightside up, then unclip and slip through the hole to remove the carabiner, then slide the bolt open. The run door has a hasp with a turn latch (the hole the lock slides through turns to also act as a latch- not sure of the technical term for this type of hasp!) I slide a carabiner through this and flip it too. I don't have a picture of either, but if you need one I can take one.