Rabbit seems to be the best bait round our way, also pheasant carcasses. Catch all ours when the bait is stinking rotten. On the traps i use the bait is attached to a bar inside the trap when the fox pulls the bait the door slams shut. Seems to work though had 4 this year, 9 last and 12 the year before. Make sure the floor is covered with soil so they cant feel the wire when going in.