Try mixing peanut butter with canned whole kernal corn mixed with some cotton/polyfiber (fish tank filter material, old carp/catfish trick used /staplewith desolving baits!!!!) and nail a glob of it to a piece of plywood,.....1'X1' or 2'X2'. Spread a thin layer of pb here and there around the plywood to hide your scent and to give them a little "false security" walking on the wood!!! The wood makes a good target stand if your barn floor has little dips, manure, etc., and the fiber keeps them stationary/busy for clean shots. Let them work the cotton glob for a night, reset the next afternoon and then "ZAP" them the next night!! Good Luck!!! tjk