You folks who have livestock guardians and angel-dogs that have never harmed so much as a feather on a chicken's tail, please tell me what I am doing wrong. I have a Great Pyrenees. Not a dumb dog, about 8 months old. Did obedience training perfectly. Knows many tricks and believes I am alpha. We gradually introduced him on-leash to the chickens, and he behaved well, so he went on to off-leash. He tried to play a little with a rooster once, but was immediately sorry for it, and has not had any mistakes since, oh, October 1 2007. That's what, almost five months? that he's been working with the chickens in the barn, off-leash, with no mistakes. He is good with the cats. Well, he tries to lick them, which they hate, but he's good around the house. He's not teething anymore and doesn't chew anything inappropriate. Today, as usual, I get home and go into the barn to collect him and bring him in for dinner. What do I find but my puppy, face-first in a dead rooster, chomping away, blood up to his ears. A rooster that was perfectly healthy this morning, I might add, and which I rather liked. I don't get it. He has virtually no prey drive, three vets have confirmed. He was bored silly by chickens for months on end, and behaved exactly right--he'd go in the barn, slurp some water, sniff the chicken feeders, sniff the roosts, then flop down in a pile of straw. Barked and growled at unknown people and at opossums. How can he not bother the chickens for months and months, then screw up like this? What am I doing wrong?