Feeding live rats for the first time....

I realize it's better to buy the feeders in advance so they can be fed and hydrated better than they were in the store.

Is there a certain amount of time I should buy the rat in advance? Also, I've heard single rats don't do so well, but I'd really rather not be keeping rats all the time. Not to mention, I don't want them to get too big. (I was told my snake eats mediums).

What I had in mind was maybe buying the rat on Wednesday for a Saturday feeding.

Should be fine Chris. It will give the rat a couple of days of decent feeding and access to water and that never hurts as far as I'm concerned to help make it a better dinner for your snake.

Since this will be your first live feeding with this snake and you've never seen it take down live to judge it's skill, personally I'd choose a small rat rather than a medium. Most BP's don't need to take a medium rat ever week anyways. Mediums are just that much bigger and I like to err on the side of caution for first live feeds until I know a snake and it's live hunting abilities with bigger rats.

Also just in case the snake refuses, a small rat gives you more time to have to house it without it outgrowing the snake.

Going with a small definitely sounds like a good idea. As always, thanks :)