David Moe:

Alberta is the only province in Canada that does not have any rats and is, in fact, the largest inhabited area on the planet that is rat-free. Rats had to come from Eastern Canada, and it’s a long walk, so it was not until the 1950s that they finally reached Alberta. When they did, the Alberta government was ready for them: They instituted a very aggressive rat control program that killed every single rat that crossed the Alberta/Saskatchewan border.

The Agricultural Pests Act of Alberta, 1942 authorized the Minister of Agriculture to designate as a pest any animal that was likely to destroy crops or livestock; every person and municipality had to destroy the designated pests. Where their pest control was not adequate, the provincial government could carry it out and charge the costs to the landowner or municipality.

Rats were designated as pests in 1950. An amendment to the act in 1950 further required that every municipality appoint a pest control inspector. In 1951, conferences on rat control were held in eastern Alberta, and 2000 posters and 1500 pamphlets titled "Rat Control in Alberta" were distributed to grain elevators, railway stations, schools, post offices, and private citizens.

Between June 1952 and July 1953, [more than 140,000 pounds] of arsenic trioxide powder were used to treat 8000 buildings on 2700 farms in an area 12 to 31 miles wide and 186 miles long on the eastern border. Some residents were not informed that arsenic was being used and some, allegedly, were told that the tracking powder was only harmful to rodents. Consequently, some poisoning of livestock, poultry, and pets occurred. Fortunately, Warfarin—the first anticoagulant rodent poison—became available in 1953; Warfarin is much safer than arsenic, and in fact is prescribed to some heart patients as a blood thinner.

The number of rat infestations in the border area increased rapidly from one in 1950 to 573 in 1955. However, after 1959, the numbers of infestations dropped dramatically.

The provincial share of rat control expenses increased to 100 percent in 1975. All premises within the control zone from Montana to Cold Lake are now inspected at least annually. Rat infestations are eliminated by bait, gas, or traps. Buildings are occasionally moved or torn down, and in some cases, rats are dug out with a backhoe or bulldozer. In the early days they also used shotguns, incendiaries, and high explosives to control rats. It was something of a war zone.

Hundreds of suspected infestations are reported each year, but most sightings turn out to be muskrats, pocket gophers, ground squirrels, bushy-tailed wood rats, or mice. However, all suspected infestations are investigated.

A few white rats have been brought in by pet stores, biology teachers, and well-meaning individuals who did not know it was unlawful to have rats in Alberta, even white lab rats or pet rats. White rats can only be kept by zoos, universities, colleges, and recognized research institutions in Alberta. Private citizens may not keep white rats, hooded rats, or any of the strains of domesticated Norway rats. Possession of a pet rat can lead to a fine of up to $5000.

In 2004 someone released 38 rats in Calgary. By the time the rat control officers arrived, most of them were dead. The local residents had formed a posse and killed them with brooms, 2x4s, and shovels. If the authorities had caught the culprit, he could have faced a $190,000 fine (38 x $5000)—assuming his neighbors didn’t get to him with brooms, 2x4s, and shovels first. Albertans don’t want rats.

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