Over three years ago I had an owl box installed in my back yard to address the gopher problem. Disappointingly, no owls have taken up residence ... until last Sunday. I have heard barn owls in the neighborhood, not the hooting kind but rather the mumble/screech kind. I have even heard them on my balcony at night. Sunday night when I went in my back yard to gather green waste for pick up I heard them IN THE BOX! Monday they thumped around in there all day. Even though we set up an outside camera we haven't been able to catch them entering and exiting. Will keep trying.