Welcome to CSI: Poultry. I have a batch of 22 8-week old chicks that live in a wire-fenced tractor. Up until a few nights ago I would put them in a sturdy (but stuffy) cage to sleep, but then decided they would benefit more from the fresh air. They now sleep in a big pig-pile by the side of the enclosure. Each night I place boards & other materials against the side where they're sleeping to prevent any critter from reaching in & grabbing them. This morning I found one chick dead, its neck twisted, but no wounds to be found. There weren't any feathers fallen off, no holes in the wire side, no signs of a struggle. I have my theories, but want to hear what you think without influencing you.