I forgot to mention. Don't get all caught up on using hay. You can rake up a pile of bean stalks and chaff, or pile up a bunch of corn stalks and accomplish the same thing. They hunt those piles for mice and rodents. Just the visual of a pile in an otherwise flat field is often enough to get them to investigate. Then I typically make a blind trap set, and use scissors and cut up whatever the pile of made of for the final trap covering. It blends perfectly.