We have some 4 week old Cornish Cross chickens in a tractor about 200 yards from the house. This morning, when we went out to feed, water, and move them, we saw 3 birds decapitated, with their heads completely ripped off--but not eaten, and claw/teeth marks on their backs. There wasn't a lot of blood around, if any. Almost looked like the predator had sucked the blood out. No parts of the chickens were eaten. No other birds were touched. Someone had left the door on the top of the tractor open by accident the night before--the predator did not dig under the tractor, it climbed in. Can anyone help identify this predator? We think it's a possum. Any ideas?