What predator can avoid the tripping mechanism and reach over and take the bait out of the trap? Twice now something has managed to get a free meal off of me. Last night it was pepperoni wrapped in a paper towel and once before a hunk of rotting beef. My husband had been tie wrapping a can of cat food to the back wall, but had no takers. It is scary to think an animal is smart enough to avoid a human made trap. Any advice on how to catch the darn thing.?