It is up to you whether or not you feed live mice. I typically prefer to feed mine prekilled or frozen-thawed. Feeding live is a huge risk to the snake (it can be bitten and bleed to death) and, in my opinion, cruel to the mouse as it has no chance to escape as it would in the wild. Not to mention, your BP won't be eating mice forever, and rats can inflict some nasty wounds. Better to switch now than later.