This is supposed to be a map showing (in red) which parts of the world contain brown rats. The Canadian province of Alberta claims to be rat-free. Since about 2007, there have been disputes and edit warring over if this map should have a hole in Canada representing Alberta’s population of zero rats. Check out the lengthy file history and the dispute on the talk page.
File created by Jrockley, Public domain, via Wikimedia Commons
It has taken New Zealand decades of struggle to rid a few tiny islands of rats. Apparently they just needed to ask Alberta how to do it. Absurd.