An official website of the United States government
Here's how you know
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Geographic origin of resistant rodent populations. Warfarin resistance areas in Europe are shown and locations where resistant rats were trapped in the wild are indicated. Different mutations are represented by different hatching.