It’s not your imagination. San Francisco is becoming rattier — literally. According to a new study, San Francisco’s rat ...

Basically, the future is shaping up to be a lot rattier. More rats, in short, is not great. These animals can carry dozens of pathogens and parasites, such as the bugs that cause hantavirus ...

Scientists sorted through data from more than a dozen US and foreign cities to determine what is driving the increase in rat populations in urban areas.

Warmer winters, denser living conditions, less vegetation and limited rat control resources also contributed to the growth in urban rat populations.

Urban dwellers in Washington D.C., San Francisco, Toronto, New York City, and Amsterdam might have seen rats scurrying across their cities — and they're not imagining an influx. Rat populations ...

Winters are getting warmer and shorter as the climate changes. That's helping rat populations grow in several U.S. cities.