Ok well I just got back from buying my first pair of breeding feeder rats, These are HUGE (well bigger than im used too). They gave us a female that is already pregnant. I had some 10 gallon tanks to put them in but when I saw then I quickly moved them up in size of enclosure. I looked at the male and female and I cant tell the difference except the female is smaller and her belly is really plump, is that normal for females when they are pregnant? Oh and the rats were priced at $8 each but they sold them to us for $6, so hopefully thats a good deal and will pay for its self. Im waiting until I get some more big tanks or lab style cages before I get more, maybe I can talk them out of one of the Freedom Breeder racks (they have too many anyways )