The Chicago Rat Project

Brown rats (Rattus norvegicus) create challenges for public health and infrastructure in cities around the world. The Chicago Rat Project started in 2018 with the goal of studying Chicago’s rats to improve management and prevent health risks. We use a social-ecological systems approach to combine information about rat populations and infections with survey and interview data about residents’ experiences with rats.

So far we have found that:

• Rat relative abundance is higher in alleys with more garbage, and rat relative abundance is correlated with 311 complaints in Chicago
• Rats were more likely to carry E. coli in areas with more restaurants in higher-income neighborhoods and more likely to carry Leptospira, the bacteria that causes leptospirosis, in areas with more standing water in higher-income neighborhoods
• Residents living in restaurant-dense areas were more likely to see an uptick in rats during the COVID-19 pandemic
• People of color were more likely to be exposed to rat urine in the home compared to white residents, suggesting that rats should be considered another environmental health burden for under-served communities [pre-print]
• People who see rats in their house daily had 5 times higher odds of having high depressive symptoms compared to people who see rats less frequently [preprint]