We've been out of town, and our chicken sitters called in a panic last night while we were driving home. Three of our four didn't come home last night, but our friends could find no signs of a struggle. We're out in the boondocks, and what predator problems we have had have been at night, so we had our friends come over and let them out in the morning and then come back and lock them up at night. That won't happen again, we'll just leave them in the run....but back to the odd thing. There's no sign of a struggle anywhere. Not one single feather from three birds that I know would put up a pretty good fight if attacked. What could take all three without one single feather left behind? I've been all over our ten acres, and in all of our chickens' favorite resting and foraging spots, and there's no sign at all.