Alberta is not a very welcoming environment to the human-dependent Norway rats that article talks in the first place. It's a huge, empty area that, for those r

Alberta is not a very welcoming environment to the human-dependent Norway rats that article talks in the first place. It's a huge, empty area that, for those rats, is a barren wasteland with a few tiny oases of human population - and the Albertans still have to constantly clean out new infestations. New Zealand is vastly more welcoming to the invasive species it has. In a decade or three, they'll call it "good enough" on the mainland islands and spend a great deal of effort in perpetuity to keep pest levels under a modicum of control.