My first thought was that they had no idea it was a fox and were just trying to kill something. The reason poultry feed has to be scattered over a wide area is that they will peck through other chickens, killing them in the process, before turning and eating from an open spot if they feel they need to compete for food. Turkeys are worse than chickens. An amish turkey farmer once told me that if you leave a bucket of feed with the turkeys you’ll end up with a bucket of dead, half-eaten turkeys and all of the feed you started with.