Alberta is one of the world’s only places without a breeding population of rats – thanks to skilled pest controllers and a take-no-prisoners approach

From his base in rural Alberta, Phil Merrill has fielded phone calls from around the world. And whether they’re dialling him up from New Zealand or Ireland, the question is always the same: how do you get rid of rats?

For nearly 50 years, Merrill has been on the frontlines of a singular – and victorious – battle, transforming the western Canadian province into one of the world’s only rat-free jurisdictions.

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“We’re winning,” said Merrill. “The poor rat, he does really well back in the 18th century, but in this century he’s struggling.”

Bordered to the south by the US state of Montana and flanked by the Canadian provinces of British Columbia and Saskatchewan, Alberta – a province of 4 million people that covers an area slightly larger than France – does see the occasional rat.

But save for a few exceptions over the past decades, the province does not have any breeding populations of rats.

“We don’t have any rats, but everyone keeps sending us the damn rats,” said Merrill. “Guys come in from holidaying down in Palm Beach, they come home with their trailer and they bring a rat. Or the produce truck comes from who-knows-where and they’re unloading it and the rat jumps off. So we actually get about two rats a month.”

Merrill started with the province in 1971 as a pest-control officer, two decades after the province’s first recorded rat sighting. Amid concerns over the damage that rats could do to Alberta’s agricultural sector – the province’s second largest industry – an ambitious plan was launched to keep the rodents out of the landlocked province altogether.

“When I first started, I thought, aw hell, we’ll never be able to maintain this,” said Merrill.

Facebook Twitter Pinterest A 1948 poster from the Alberta public health department. Photograph: Provincial Archives of Alberta

The lofty goal came with a multi-pronged, take-no-prisoners strategy; a poster campaign urged residents to kill the rodents on sight, pet rats were banned and regular inspections were launched along what came to be known as the rat control zone – a 29km stretch of the provinces that butts up against neighbouring Saskatchewan.

Key to the strategy is Merrill and his team of six who regularly comb through 3,000 farm sites along the rat control zone, dropping poison as needed. A wider network of some 150 contacts across the province also helps Merrill eliminate any rats that might turn up.

In 2015 a hotline, 310-Rats, was launched, giving Merrill and his team eyes across the province.

While 95% of the calls that come in these days are misidentified rodents – owing largely to the fact that many Albertans have never actually seen a rat – Merrill estimated that the tip line gets two viable rat reports a month. “If we didn’t get that call, we would lose it,” he said. “If people didn’t phone us and say they saw a rat, how would we know?”

The result has been remarkable. “When I first started back in the 70s, we had about 50 to 70 infestations along the border a year,” said Merrill. “We’ve got it down to about one or two.”

Some of the credit goes to farmers who have gotten better at protecting their feed, he said. But even as the number of rats has dropped dramatically, the province has refused to let its guard up.

Facebook Twitter Pinterest Phil Merrill, in Langdon, Alberta. Photograph: Ashifa Kassam/The Guardian

Anyone looking to transport a rat through the province – say someone who is moving from North Dakota to Alaska and wants to bring their pet rat along – needs a permit. As do zoos and any university that wants to carry out studies on the rodents.

Not all rats found in the province are killed; some have been deported. Merrill and his team once pitched in their own funds to fly a pet rat back to British Columbia rather than kill it. “The person loved the rat and they didn’t want us to kill it so everybody throws in 10 bucks and they put it on a plane,” he said.

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The total cost of the province’s battle against rats hovers just under C$500,000 ($380,000) a year – a relative bargain in light of a 2004 report that estimated rats could cause as much as C$42m a year in damage to Alberta if left unchecked.

“That’s probably exaggerated,” said Merrill. “But we look at it as a real economic advantage. If our farmers had rats, wooden bins are destroyed in less than six months.”

With a grin, he slipped in another, more subtle, reason behind the province’s decades-long battle: “It’s a personal pride that we don’t have any rats.”