How old/big is your BP? The one I used to have was several years old and about 5 feet long, and he only ate a medium-sized rat every 4 to 6 weeks. Larger and older snakes don't eat as often as the smaller and younger ones.

The rat will live fine off a few crackers and bread pieces a day. They'll even eat crickets and worms if you give them that. Or cat food. Heck, feed it a hot dog weenie, and it'll think it's died and gone to heaven. Or peanut butter on a cracker. They LOVE that. (I used to actually have rats as pets. They can make pretty good pets with time and effort.) Make sure to put a little something in there for some water for it to drink, too, since you're having to wait for your snake to get hungry.