Here are: Charlie the cat looking at and listening to (clockwise from the white rat): Jadis the Ice Queen of Narnia, Y2K (Yersinia the second of Kathryn), Moonshine, and Portabella. When I got my rats I initially took the only two "crawlers" (Port and Moonshine)... then after getting our larger cage I wanted to fill in the group with two more rats that were different hues of rat.
Note: All of the rats in this picture have since passed on to the little ratnest in the sky. At two year of age they all got different forms of cancer and died. It was very, very sad, but I think I'm almost ready for more!