![Midday on WNYC show](https://d3dthqtvwic6y7.cloudfront.net/podcast-covers/000/031/143/small/wnyc-s-leonard-lopate-show.jpg)
Summary: Gray squirrels may seem like they've always been in New York City, but they're actually a fairly recent immigrant. Etienne Benson, Assistant Professor in the department of History and Sociology at the University of Pennsylvania, explains why the rodents were introduced into cities at the end of the 19th century. His paper “The Urbanization of the Eastern Gray Squirrel in the United States” is in the Journal of American History.