"Rats are incredibly good swimmers. And they can climb." Ostfeld added: "Rats are highly social individuals and live in a fairly stable social structure. If this storm disturbs that, rats could start infesting areas they never did before."
Read more: http://www.businessinsider.com/what-happened-to-all-the-subway-rats-during-hurricane-sandy-2012-10#ixzz2AqtuxBhN