how to tell my pet rat from a boy or a girl

Question
Hi, I just got my pet rat couple days ago. Well I know that a girl rat has nipples and a boy doesn't. I also know that a girls genitals are closer together, but I just don't know how to tell with my eyes. I'm guessing its a girl, but its solid white and hard to tell. And I got her out of a pet store so I think she's about 4 weeks old. Is there any other way to figure out if she's a boy or girl.


I'm really hoping it's a girl! But the pet store said it was to early to tell. Can you HELP!!

Answer
As usual, the pet store is absolutely INCORRECT.  Most experts can tell the difference between sexes the day the babies are born!!!!  

Check this site out to compare the difference and maybe you can teach the pet store employees a thing or two about rats!!!!!!!!  Its obvious they are clueless.


http://www.ratz.co.uk/sexingrats.html