I'm new to chickens and decided to take my girls/boys outside today because it was so nice. I put all 9 Orphingtons in a dog pen, threw a sheet over it for shade and let them peck in the grass. I pulled up a lawn chair to study (grad school - boo). My dog (Aussie) is laying next to the pen. My neighbor's Lab is laying in her lawn napping. Both yards just have an invisible fence. All of a sudden an American Staffordshire comes busting over the hill. The neighbor's Lab lays into it and I run over to help the lab. We chase it off. I give the lab a once over and she looks ok and then I get the owners to check her out too. That said if Shadow (the lab) hadn't been out the dog's next stop would have been my pen of chickens. It would have been one heck of a fight as my dog is very protective of the chickens. That said I don't think I'll be letting them out again without a real fence around them, not just a flimsy pen. With a hot wire, and a shotgun and land mines (ok, I'm going over board). I will be really harassing my husband to put up a fence now! I just wish it wasn't so expensive to fence 3 acres.