Marshmallows work best if you want to trap just raccoons. But anything works. We used sardines, tuna fish, marshmallows and strawberries. A friend of mine said she can set an empty trap and they will go in. You don't really need to get them used to it. You can also cover the trap with a smaller meshed wire, or a trash bag, to keep the coons from reaching through the bars from the outside and grabbing your bait. That might be how your trap was sprung. This is the distasteful part of having chickens, as I hate to trap the wild critters. If you don't get rid of the raccoons, though, you'll have mayhem.