Try this:
Thaw out the mouse/rat and put it inside the BP warm hide and then leave the room / turn out lights. Placing it in the warm hide allows it to heat up the meal a bit or keep it warm. This has worked very well for me with pickier eaters and I have one female that eats exclusively using this method. It will usually be gone within 1-2 hours, but I would wait a day and see if they take it.