Sexing Rats: Alpha Centauri Stud
Alpha Centauri Stud no longer breeds rats, but it still has great detailed photographs on the visual differences between girl and boy baby rats. Click the image to the right to visit the home page for the site for extensive photographs and line drawings. Or, here is the direct link to the Rat Health Care & Information site on Sexing Rats: http://www.ratz.co.uk/sexingrats.html. Please visit the Alpha Centauri site for many valuable articles on rat care.
Careful: Separate baby boy and girl rats from each other, and the boys from their mother, by age 5 weeks, or the females will become pregnant and you'll start all over again!