I think my solution is going to be putting a door on the small part of their run (4'x8') that goes out into the main area. The hen house is butted up against and opens into this little run so I could lock that run in the evening or even when we left out of town and they'd still have access to the outside, just not as much as normal. But that run is the covered part of their outside area so they spend a good majority of their time in there anyways (shade and rain protection). It's made of very heavy duty wire with squares too small for a coon or possum to get through. I suppose if something wanted to tunnel under the chickens could still be in danger, but I can't keep them in Fort Knox. :?