WASHINGTON (AP) — Rat infestation in many world cities appears to be soaring, especially in Washington, and a new study blames warming temperatures, urbanization and other human actions.

Based on individual trends within cities, Washington was by far the leader in rat increases, followed by San Francisco, Toronto, New York City and Amsterdam. NBC Universal, Inc. Rat infestation in ...

A first-of-its-kind examination of trends and reasons in hard-to-count rat populations uses rat sighting reports in 16 cities around the world. In 11 of those cities, rat complaints have increased ...

WASHINGTON (AP) — Rat infestation in many world cities appears to be soaring, especially in Washington, and a new study blames warming temperatures, urbanization and other human actions.