I had a lot of trouble switching my BP to f/t. I tried everything anyone had ever suggested to me. Heating it in water, using a blow dryer to the rats head, dragging the rat on the bottom of the cage, dangling it, and basically everything else you can think of. Out of options, I decided to put the thawed rat (in a sandwich bag) in a sink and let hot water beat on its head for about 5 minutes before dragging it in front of my BP. She took it right away and has missed few feedings since! So if you run into problems, give it a shot!