For the past couple of months, I've been trying to persuade my BP to switch to rats. I've tried all the suggestions (prescenting by thawing mice & rats together, thawing in enclosure, not moving him to feeding enclosure, trying pinky rats, etc.) Nothing was working. He'd either reject everything or take the mouse but not the rat, and if I offered bigger prey it was even worse. He was losing weight, so I decided to go back to the acceptable prey temporarily and try switching to rats again in the spring. I also decided to increase in prey size gradually rather than radically even though this guy should be eating larger prey.
Success! I'm posting photos, but first let me tell you a bit about the first mouse. I made it act as if it was on the branch the BP was on and backing away from the BP. Great interest! BP grabs & wraps mouse and promptly falls off the branch! I was laughing so hard I forgot to take any photos. After he got that one down, he went back up on the branch--after all, where there was one, there might be more, right?
Here's the next mouse wrap (using the same technique of twitching the mouse along the branch away from the BP):
He felt himself falling and wrapped his tail tightly around the branch. Then the biggest part of his body, on the back side of the branch, began to slip, so he tightened his neck up against the branch: