I would appreciate advice from someone familiar with how predators attack. Something pulled the tail off one of my hens recently; all her tail feathers were gone and there was a some blood, but she didn't seem hurt otherwise, and is acting normal 2 days later. My rooster is very protective of the hens (he lost HIS tail to a fox once), but he looked fine. None of the other 9 hens or my rooster were hurt, including the broody hen sitting on her eggs in side the coop, and I there are no signs of anything having dug under the 6-foot-high livestock-wire fence. The bottom 2 feet and the 2-foot apron on the outside of the fence are made of hardware cloth. I have wire strung randomly back and forth across the top of the chicken yard, and the coop is made out of an old travel trailer. We live in the Colorado mountains. A hawk or owl could have gotten into the yard through the overhead wires, but they wouldn't pull out a hen's tailfeathers, would they? A domestic cat could certainly have climbed the fence into and back out, but again, wouldn't a cat have attacked the hen in a different way? I know dogs, foxes, and coyotes can pull out tailfeathers when they attack, but they're too big to get through the fence, and I don't see any signs of them digging in. Could a fox, skunk or raccoon have climbed the fence, done the deed, then been frightened by the rooster, and climbed back out of the yard?