They usually do Bryan. I've only had one female that was a total dud at mothering. Of the rest of the females, some are better at it but all are very competent. It's always a bit more of a hassle to get pre-preggie ones, not really a savings as they are often in poor condition so you lose more pinks at birth or just don't get as healthy a litter as you get when you raise up a younger female. Since the whole point is get healthy big rats to feed off, I'm trying to avoid the pet store preggies (well until I see one like Alita and can't help giving it a home lol).