Misleading headline.

Alberta is rat-free because its government has maintained an eradication program for three quarters of a century. That doesn't mean there are never rats in Alberta. It means that, when some show up, they're reported and destroyed. To date, the costs of maintaining the program have been smaller than the economic damage rats would otherwise inflict, so it has continued.

Bowden is nowhere near the border, so this is a little concerning. Hopefully it was just an isolated individual that made it in through a shipment.