Try leaving the F/T rat on a paper plate or on top of a hide in the cage. Dottie went off food back in Oct or Nov and has just started eating again this past few weeks. She too was active and stuff during the winter fast. I never bothered to weigh her or anything. I saw her drinking and I found urates so I just went with that. I tried a F/T rat for her every 2-3 weeks. Then a few weeks ago, she seemed kind of interested so I left the rat on top of her hide and in about 5-10 mins she slithered up there and ate it. Now she is back to striking at the rats. As long as the snake looks ok, is drinking and acting fine and the husbandry is ok, I wouldn't worry. They will eventually eat. An adult BP will not starve itself to death. Babies are a different story and some need to be taught how to eat lol.