The brown rat and the house mouse were both introduced and their habitat range throughout the Eastern U.S. Weasels such as the fisher and short-tailed weasel are found in the northeast. The eastern chipmunk, fox squirrel, eastern gray squirrel and the woodchuck are found throughout the region, while the southern flying squirrel and northern flying squirrel are more common in the southeast, the American red squirrel is more common in the northeast. The least weasel is native to the Appalachian Mountains.