I'm surprised they didn't mention it in the article, but Alberta (a province adjacent to British Columbia on the east side) is mostly rat-free (infestations per

I'm surprised they didn't mention it in the article, but Alberta (a province adjacent to British Columbia on the east side) is mostly rat-free (infestations per year at 0 or in the low single digits since 2000. It is entirely land-locked though. As far as I know there have been no adverse effects. They started aggressive rat control in the '50s.