It took me a long time to figure out that BPs really can eat some pretty big rats, as long as it's not too much bigger than their thickest point. Having figured that out I stepped up earlier than expected, not only to rats, but something quite a big bigger than what she'd previously had.

This was the result:

http://fire-eyes.org/gal/v/ob/n/rep/sn/m/j/fr/

It may look extreme, especially when she's getting it past her mouth, but she really had no issue with it. By the way it is not a good idea to feed them simply because they act hungry again -- Unless you are feeding them obnoxiously small meals, which is what I was doing when I was inexperienced: http://fire-eyes.org/gal/v/ob/n/rep/...h8056.jpg.html