Brown rats showed up in the Americas later, though exactly how much later has gone unresolved. Many historical accounts indicate an arrival date sometime around U.S. independence in 1776, ...

Brown rats are the undisputed winners of the real rat race.New research suggests that they crawled off ships arriving in North America earlier than previously thought and out-competed rodent rivals ...

Brown said DC’s numbers could be so high because the city encourages residents to call in each rat sighting. Public reports of rats are very useful but can be flawed, said field ecologist Parsons.