(Picture from "RATS" magazine 2005)

Wild Rats are come from Europe. Until they are discovered on the rope went climb to the tall ship call "Royal Louis" trek to the ocean. Tall ship is arrive to American. Wild Rats is discovered new life and new place. Become Wild Rats are travel on any Tall Ships carried any countries.
Wild Rats had carried flea, lice, mite, etc. But Norway Rats (Brown Rats) is fight on flea and lice. And only flea and lice toward on Rattus Rats (Black Rats) Because Black rats did not clean to kill flea and lice.  Lots people got disease cause by bites, flea, foods, etc... Thousand or Million people dead in about  1700's or past. Most people are blame to wild rats. I believe wild rats was not fault. That's happen to them. All on Earth had disease, virus, etc. Also, there had disease in dinosaurs to present .

I discover about wild rats can jump down to floor about 15 feet. (Not sure which title magazine: Willard)

Example: Look at India's Temple of the Rats. They are brown rats. Look at the people did not get sick from them. Their temple call "Karni Mata"

Photographic by Yaatra in "Flickr"

"Your Friend The Rat"

Remy and Emile.

"Your Friend The Rat"

This will tell you more about two black and brown rats' history in Dvd "Ratatouille"