Ok cool, I'll do that. To be clear, by rat crawler are you meaning the same as a "fuzzy". I don't know where you're from so we may call the same thing something different. Thanks for your help John, really.
Rats grow fast! You want something right around 2 weeks old - about when their eyes start opening and they're crawling all over the place. By week 3 they're much more mobile and eating a fair bit of solid foods - tasting just about everything they bump into.