Officials in southern Alberta have launched a new offensive in their ongoing war on rats, but believe it will take two years before they can completely wipe out the rascally rodents.
The new strategy, dubbed "Operation Haystack," will see baited, poisoned hay bales dropped around Medicine Hat to stop the flow of the vermin from the city's dump.
A nest of Norway rats was discovered at the landfill earlier this month, sparking panic and headlines across the province. Alberta had previously boasted its rat-free status for more than 50 years.
Since finding the nest, the city reported the spread of rats into its neighbourhoods. Residents have called in dozens of sightings, with some taking photos as evidence.
Ed Jollymore, Medicine Hat's waste manager, said Thursday that staff have killed 95 rats in the city since Aug. 9.
He expects it will take two months to destroy the nest at the dump. But the pests are bound to keep showing up.
"This is going to be a process of years," Mr. Jollymore said. "They still have a tendency to pop up, come back and we're looking at probably having to stay on a heightened alert for two years."
Operation Haystack is no Mickey Mouse scheme. Hay bales will be strategically placed around the city. They will contain poison that doesn't harm people or pets.
"What we are looking at is providing rats' high-end, first-rate accommodations, where they will have good comfort, protection, food and water," Jollymore said. "Rats require those three things."
The city earlier set baited traps and used high-definition cameras to track the rats. It then set bull snakes loose in the landfill to feast on the critters.
The province also sent in additional workers to help with the battle.
Agricultural fieldmen known by Albertans as the "Rat Patrol" have worked for years targeting invading rats within a control zone along the province's eastern boundary. Pet rats are also forbidden under provincial law.
The province estimates its rat control measures have prevented $1-billion in rodent-caused damage.
Despite the rat-free label, Alberta has had some isolated appearances since the 1950s.
"Just because we say we are rat-free doesn't necessarily mean we are," said Mr. Jollymore. "Rats don't respect borders. They will hop off of trucks, trains, cars, RVs."
He suspects a major flood in the area in 2010 could have brought in rats from elsewhere.
Experts say, given ideal conditions, one pair of rats can thrive and begin a chain of breeding that can produce as many as 15,000 offspring a year.