That could just mean you have very smart rodent friends. I was getting them in the house again a few weeks back, PB-baited traps were useless; they'd just lick it off without springing the traps.
I went to sausage that had always worked in the past, and they were knawing it off the pressure pads, again without springing the traps, as they were coming in from the sides.
I next tried small pieces of hollow chicken bones packed with a PB/sausage mix, and got a couple catches when they tried to pull the bone off the pressure pads.
Finally found the hot setup: glooing on pressure-pad extensions that stuck out laterally, so the little buggers would trip them if they came in from the sides.
Bingo. What a great feeling of superiority, knowing I'm smarter than rats.