We also used hardware (hardwire) cloth. Not only is it great to keep bigger predators out because it is so much sturdier than poultry wire, it also keeps snakes out. Some people also call it rat wire because it is used for large rat traps and the flooring of some hutches. I don't worry about my birds when they are in their pen.
Our set up is similar to georgiagail's except that our is across the bottom and all the way up to the top of the sides which prevents rats from climbing up and over. The top is also covered with a commercial grade tarp. The dogs' pen surrounds the chicken pen on 3 sides. (The fourth side is flush with the rest of the dogs fence other than the height difference. (Chicken pen is 5.5 feet dogs fence is 4 feet.) The dogs scare away bigger predators. I don't have any pictures. Those are usually of the chickens when they are hunting hoppers. Good luck with your pen!
