Nutria sit inside a sewage drain on Barksdale Air Force Base, La., Dec. 2. The large rodents were brought to Louisiana in the 1930s from South America for their fur. Since their arrival they have destroyed tens of thousands of acres of wetlands in Louisiana by grazing on roots of plants making it difficult for vegetation to grow and creating more open water. (U.S. Air Force photo/Airman 1st Class Joseph A. Pagan Jr.)(RELEASED)