I got interested in rats... It appears that Rattus norvegicus was named by Linnaeus, Carl von Linne, who first created the taxonomy system, in 1758. I can only guess why he called it "Norway rat". But it's probably politics. :-) Anyway, Rattus norvegicus was not the rat responsible for the Black Death in 1348-1349. It was the above mentioned black rat, Rattus rattus. So, britt, your rats should be black. A bit more at http://www.martley.org.uk/villager/archive/feb02/naturalistdiary.htm

-- erlik