...or any that I have raised, only the ones I buy. I start handling the ones I want to keep from day 2 or 3, and talking quietly to them, etc., so that they will be used to being handled even before their eyes open.
It's not too late to start, though, just handle them a lot to make up for lost time. Pick them up when they aren't near the mom, because she might nip you. None of my rat nips have ever drawn blood, or even really hurt much. They were just warnings from moms. I have seen one draw blood before, so I know it can happen.