Communal nesting vs separate birthing/nursing is a long debated topic. I have done both, but usually communal nesting is our way to go right now. I will be building a maternity rack in the summer, so we will be switching to separate preggo tubs.

On another note, rats like to be with rat company, as they are social creatures. Mom's are fine to be alone for a few days-week before they give birth, but for the male to be alone the whole time the mom is nursing is pretty harsh. I would read this http://ball-pythons.net/forums/showthread.php?t=69076