I've heard some people say that they feed their snake when it looks hungry.
What are some signs of a hungry snake?

I was planning on feeding my BRB tomorrow because thats when the breeder told me to. I'm going to feed it a live pinky rat... also because thats what the breeder told me to do. I am planning on eventually weening it off of live and going to strictly P/K food.
Any suggestions to do something else?
-Brant