There was a story sequence on where people were turned into exact clones of the same sentient rat. For example, when a husband and wife are both infected, they happen to be in a police station, under interrogation in separate rooms. Given that the rat is taking over both their minds, they are able to give perfectly corroborating answers despite not knowing what the other one is saying. It was actually a pretty clever use of the concept.
http://www.sofurry.com/view/366984
http://www.sofurry.com/view/376240
http://www.furaffinity.net/view/7803627/
http://www.furaffinity.net/view/7970700/
SF link seems to be acting up, though. Writer was Leo Todirus.