Quote of the moment:
Don't trust anyone who is capable of pounding straight maple syrup.
So, I made a handy chart for my pal Jesse Lindsay, comparing the appearance and habits of the European Black Rat (rattus rattus) and the Norwegian Brown Rat (rattus norvegicus) - so that he could determine how best to deal with the one living under his sink.
Perhaps it could help you, if you have a rat identification issue.