There are a few ways to do this. The mouse may not be warm enough try heating up more if that don't work. Try refreezing in and thawing it. The smell is worse but it lest the snake know its a mouse. Also try leaving it alone in the cage with him. I put mine in acloth bag with the mouse and put the bag back in his cage. leave him be for like an hour. Try that first.. Also have you concidered the fact that he may not be hungry. They can go weeks even months with out food and never suffer. if he gets hungry enough he'll eat