Rats are well known for carrying diseases. And as they migrate in cities, they spread bacteria that could be life-threatening to humans, according to a six-year study co-authored by Nate Stone, a Ph.D. student turned research scientist at NAU’s Pathogen & Microbiome Institute, and Dave Wagner, PMI’s executive director. The pair worked on the research alongside colleagues at NAU, Tufts University, the United States Department of Agriculture and the Centers for Disease Control and Prevention.