I am in contact with several rat rescues and people who breed rats for pets and none of them let most people into see the breeding/living areas, although all are happy to post photographs of it. The main reason is there are two viruses that someone could easily bring into a colony on their clothing, hair or nasal passages: Sendai and SDA (Sialodacryoadenitis). Once you get your colony established, if you bring in any new blood it would be a good idea to qt the new arrivals for 3 weeks. Once either of these two viruses get into your colony, the mortality can be very high--the rescue group closest to me just lost over half of their adoptable animals from an SDA outbreak.

More info on SDA if anyone is interested: http://www.rmca.org/Articles/sda.htm