I went to Tractor Supply today to look at really strong materials with which I might build a new run. I found heavy, 10ga panels which are 5' x 16', with a 2"x4" wire pattern. I don't think even a pit bull can chew through these. http://tractorsupply.com/detail.asp?pcID=8&paID=1043&sonID=356&page=1&productID=25205&zz=75134 I played with one and made it into an arch; at 5'9" tall (I'm 5'7", so I can walk in it without doing a Quasimodo imitation), it was 9.5' wide at the base; I had wanted it to be 10' wide, but I think that's close enough. I'm thinking I could anchor a series of panels to a 20' long 4x4 which is spiked into the ground with 18" rebar. I would attach the hoops to each other with Jclips or hog rings, and attach the chunnel (chicken tunnel) to a new coop I'm designing right now. This would only hold birds at least 9 weeks old, so I probably wouldn't put any other wire at the base (although I could; I found some 1x1 welded wire which is 2' tall x 15' long, and I could attach that around the base of the chunnel. If it turned out to not be as laterally stable as I hope, I can always attach EMT (electical mechanical tubing) along the "peak" of the chunnel, so it could not be compressed and wouldn't "sway" from side to side. I might need to make it 6' tall (which would take the width to 9') if I added the centerline stablizer. By building in an arch configuration, I wouldn't need to worry about a separate cover for the chunnel, and I wouldn't need to worry about sagging joists (the main problem with the coop which was on the property when I moved in) supporting the cover. Can anyone think of a downside to this, other than the expense? The panels with a 2x4 grid are $48. The neat thing is, I could add to them as I get more money; I want the chunnel to eventually be 40' long. I could save money by using the 4"x4" grid panels, which are only $31, but then I would definitely have to use other wire around the bottom, because I think a cat can pass through a 4"x4" square. I really want to get this done soon, and I want it to be able to hold off a pit bull attack. A young friend of mine was raising geese, ducks, and chickens; he had over 20 birds, and came home yesterday to find 2 pit bulls in his back yard, and all birds except his geese were dead, spread around the back yard in a gruesome, "killing-field" kind of way. I do not want that to happen to Bo and the Production Reds (minus one). I thought his dad was going to shoot the dogs, and I would not have blamed him if he had, but the son couldn't bear to see the dogs killed, too, so the owners were called. Thanks for your input!!