I have a couple of babies (one is 5 months old, the other is probably 6 months or the same age as the other) and they are currently feeding on rat pups with no hesitation at all. The Spider male used to be a trouble eater for me when I started out with him, but now he takes the rat pups with no trouble. I also switched my Pastel female over to F/T and she's currently eating rat pups as well. So, if a rat pup or adult mouse is about the same size as the largest part of the snake's body, go for it. I bet a 3 month old snake can definitely take a rat pup or adult mouse.

I don't use a separate freezer, I just put the rodents on the highest shelf in the freezer so no one freaks out LOL.