Make sure that the prey is thoroughly thawed, then use a blow dryer to heat it up to about 99-100F. That is the natural body temp of a live rat and it will give them a good signature to aim at. If they don't seem interested right away, try laying it about 2-3 inches in front of their hide, turn out the lights and leave them alone for the rest of the night. If it is still there in the morning, throw it away. Sometimes you may just have to use tough love and play the waiting game. If it comes to that, make sure you keep track of their weight, in case you have to eventually give in and offer a live prey. Good Luck!!!