Try putting some bait out without the trap, after they get a taste for your bait place it on the traps, I use peanut butter infused with cotton swabs so they can't just take the bait and run. also if you touch the traps with your hands they may ignore it. Dip the traps in boiling water then only handle them with clean sterile latex gloves, I had a rat that loved papaya it took a week to turn his ass on to peanut butter then BAM!!!!!
GL