How Canada’s Cities Got So Repulsively Ratty

This past July, while every other person on the internet seemed to be enjoying “brat summer,” I was in the throes of rat summer. Mostly, the rodents I collided with across Toronto were flattened, desiccated—extremely dead. One dewy morning, I skirted the pink, sidewalk-smeared guts of a small furry body on my way home from the gym; another day, another rat, stiff with rigor mortis on the curb in front of a string of downtown restaurants. The live ones often manifested as dark blurs in my peripheral vision, but one evening, I clocked an entire rat family casting outsize shadows as they scurried under the streetlights. These sightings became so frequent that my two roommates and I bought a small chalkboard on Facebook Marketplace and started our own daily tally. The record? Six, caught racing through a residential neighbourhood, all within the span of a half-hour. 

It’s not just me, and it’s not just Toronto: Canada’s cities are visibly rattier than ever. Out in the Maritimes, the populations of P.E.I., Nova Scotia, and New Brunswick are ballooning. That’s led to a lot of construction and land-clearing, which has sent rats running into urban areas. On the West Coast, B.C. banned some forms of rodenticides over poisoning risks to other animals in 2023. Since then, Vancouver residents have documented a growing rodent presence across the city. (One viral video on social media shows rats—two, maybe three dozen—swarming outside the Burrard skytrain station.) Rats have been found swimming in toilets, gnawing through garbage cans and children’s car seats and, in Waterloo, Ontario, crawling out of the ceiling of a Tim Hortons. The question now is: how do we take our cities back?

For all the panic, no one knows the exact size of Canada’s current rat population. They tend to die fast and breed even faster, and a head count is obviously impractical: inspectors can’t track the movement of every single specimen. Still, it’s fair to say they’re on the rise. In the last three to four years, Orkin Canada, the country’s largest pest-control company, has reported a steady uptick in rat-related complaints. And more than 60 per cent of health inspectors across Canada surveyed by Abell Pest Control confirmed an undeniable increase in rat activity, a trend they expect will only escalate over the next three years—a boom with no singular cause.

Some experts speculate that the warmer temps that come with climate change could be contributing to the rat renaissance, possibly extending the rodents’ reproductive seasons, along with those of ticks, roaches and other vermin. Veterinary pathologist and epidemiologist Chelsea Himsworth, who founded the Vancouver Rat Project in 2010 with the goal of filling in some of our rat data gaps, points to the wreckage that comes along with extreme weather—which includes scattered garbage—as a trigger. “Rats capitalize on chaos,” Himsworth says, invoking the aftermath of Hurricane Katrina. After the 2005 storm left 80 per cent of New Orleans underwater and covered in debris, the city’s rat population skyrocketed, with the local Mosquito, Termite and Rodent Control Board receiving as many as seven calls per day. More recently, after Hurricane Helene slammed into Florida last fall, rat reports spiked halfway up the eastern seaboard. 

Back in Canada, a rise in our human population could be to blame. In 2023, the country grew by more than a million people. If the average Canadian produces 684 kilograms of trash per year, we just added another 820,800,000 annual kilograms of potential rat food to the pile. The housing boom isn’t helping, either. More than 80,000 new rental projects kicked off between 2022 and 2023—a generational peak—and many are ousting rats from their burrows. And then there are the transit digs: since 2019, Ottawa’s ongoing LRT project has resulted in rats fleeing to surrounding properties. When Metrolinx set its excavators to work on Toronto’s forthcoming Ontario Line in 2020, rats chewed through the concrete in one resident’s basement, costing her nearly $2,000 in exterminator fees.

Rats also wreak plenty of havoc on our health: they’re vectors for pathogens like leptospira, salmonella and E. coli and eat or contaminate enough food to feed 200 million people each year. There’s also the psychological toll, the ick factor of it all. A recent study out of Johns Hopkins determined that people who experience infestations—“an under-appreciated stressor”—are much more likely to experience depressive symptoms like sadness and anxiety than those living blessedly rat-free lives. Earlier this year, I spoke with Joy Fan, a 25-year-old account manager who shares an apartment with her mom in an old low-rise building on Vancouver’s south side. Fan understood that living in a major city came with its ratty rites of passage—and she’d long made peace with the delicate nightly pitter-patter of mice in their walls—but she wasn’t expecting to see rats running roughshod over her entire block. 

This past summer, after one of Fan’s neighbours reported a ghastly stench, they found one rotting outside their building, belly up, its neck shredded by some long-departed predator. Fan gamely helped with the clean-up, donning a pair of rubber gloves before slipping the deceased animal into a plastic bag. “I didn’t want it to stink up the place,” she says. “I later found another one in a neighbour’s yard, so I grabbed that one as well.” After several exterminator visits (also targeting the mice) little headway has been made. Fan’s building is at least 60 years old, she says, so barring a full-scale demolition—which isn’t planned—she’s out of options. 

Outside of the home, rats are extremely bad for business. A 2023 study revealed that the global cost of rodent invasions totalled about US$3.6 billion between 1930 and 2022; since not all invasions are reported, experts say the true cost could be more than 80 times higher. Yukoner Saba Javed experienced this public nuisance first-hand. During a trip to Vancouver last February, she was halfway through an evening at a “nice” bar when a fellow patron leapt off her stool with a yelp. Something warm, furry and undeniably alive had tumbled out of the ceiling and right onto her lap. “The bartender’s solution was shots for all,” Javed recalls. “Everyone was so excited about the free liquor that, five minutes later, no one remembered the rat.”

This complacency (or, maybe, helplessness) was echoed by a friend of mine who worked the graveyard shift stocking shelves at a major grocer in B.C. during the pandemic. He simply got used to seeing rats tap dance their way across cans of fruit and beans, occasionally feasting on the wrappers and leaving behind trails of feces. I asked if he reported them to management, and he said they already knew; they just couldn’t do anything about it. When a rat startled him one day as he stocked the dairy crate, his only defence was a fellow co-worker. “He stomped the little guy to all hell,” my friend said. “Then we held a funeral for poor Jerry.” 

The traditional approach to getting rid of rats is a combo of bait and trap. Many traps use anticoagulants like bromadiolone or chlorophacinone to finish the job—when rats ingest them, run-of-the-mill injuries like cuts and bruises turn fatal, with the rodents succumbing to a slow death by internal bleeding. The city of Ottawa, for example, started baiting its sewers this year to reckon with its rats. In 2021, two years into the city’s second phase of LRT construction, it received almost 1,200 complaints—a 645 per cent increase from 2018. (In 2021, one woman in the city’s Heron Park neighbourhood killed nearly 500 rats in her backyard alone.) “The Pied Piper is not going to get these things out of our city,” councillor Tim Tierney said at one city meeting.

But while the somewhat gruesome traps are suited to an enclosed environment, like a house, they’re a limited mitigation tool on a city-wide scale. According to Kaylee Byers, an assistant professor at Simon Fraser University who’s been researching rats in Vancouver for more than a decade, there are lots of other things to nibble on. And even if traps cull rats within a single block, that won’t stop a nearby pack from moving in. “I think of it as a tug of war,” she says. 

There is one place in Canada where the humans are winning: Alberta, which claims to have been rat-free for more than 70 years. (What that really means is that there are no resident invasive rat populations, even if the odd little guy still hitches a ride or crosses the border from time to time.) Karen Wickerson is the province’s foremost rat and pest specialist, also known as “Alberta’s Rat Lady.” She attributes the area’s world-famous rat absence to natural geographic advantages. It’s too cold for the critters to survive up north and too mountainous to the west. The southern border, abutting Montana, is sparsely populated with humans and, therefore, offers precious little food. That leaves the eastern border with Saskatchewan, Alberta’s 600-kilometre Rat Control Zone, which is patrolled by Wickerson and a team of officers—sporting proprietary “Rat Control” vests—every spring and fall.

The provincial government initiated the program in the early 1950s, when rats first breached the Saskatchewan border and authorities worried about damage to Alberta’s thriving agricultural sector. Thanks to a combination of rodenticides, traps, full-on building removals and digging rats right out of the ground, the province was able to reduce the zone’s infestation count from an average annual high of 600 in the ’50s to zero in 2023. In its urban areas, Alberta relies on citizen monitoring, a “see something, say something” policy passed down through generations. In 1951, the province even distributed “Keep Rats Out Of Alberta” pamphlets to mobilize the public. 

A recent population surge—of 200,000 more residents between 2023 and 2024—threatens to undo Wickerson’s progress. In response, the Alberta Invasive Species Council just launched a new public awareness campaign to counteract it. “We need people to literally rat on rats,” says Megan Evans, the council’s executive director. In the event of a sighting, Albertans can call 310-FARM or email [email protected], at which point an investigator asks them a few questions: can you describe the animal? Where did you see it? And: can you send a photo? Wickerson says that the majority of reports end up being muskrats. Sometimes, they’re squirrels.

Alberta is, of course, an anomaly; less topographically gifted places will have to explore other rat-reduction routes. Chicago, America’s rattiest city for 10 years running, has tried a few experimental ones, like releasing 1,000 feral cats into the streets (contentious and ultimately ineffective) and stuffing dry ice into burrows to cause suffocation (effective but inhumane, per PETA, and also illegal, per the EPA). Over in Europe, they’ve been deploying a cutting-edge invention called the SMART Box, a fancy, poison-free trap made by the Swedish pest control company Anticimex. When an unlucky rat scurries in, it trips sensors that trigger an electrical current. Once zapped, the rat body is automatically dumped into an internal bin, ready for pick-up by a pest expert. Each box even has its own cellular signal and sends real-time data on their rat counts to the SMART offices, data that could eventually help cities track their own numbers.

One of the buzziest rat-fighting methods is an update on a relatively old technology: birth control. An Arizona-based company, SenesTech, has developed baits that reduce rats’ fertility for 45 days after consumption by inducing menopause or limiting their sperm production. SenesTech also claims the bait is metabolized quickly enough that it won’t end up in the bloodstreams of any other species, unlike conventional rodenticides, which can be absorbed by any unlucky animal that takes a bite. Bonus: compared to traps, this method is far less bloody.

Laine Johnson, an Ottawa city councillor, has been pushing for the city to test SenesTech’s products. “We’re creating some of these conflicts between rat habitats and people, and we want to make sure we’re doing everything we can—as efficiently and cost-conscious as we can,” she said this past June. But SenesTech won’t be Ottawa’s silver bullet. It could take Health Canada two years to approve the contraceptive and, even then, experts aren’t hanging their hopes on it. Himsworth says that a population can rebound in as little as four weeks following an extermination campaign, and some experts estimate that a pair of rats can pop out as many as 1,250 offspring annually. An entire city swarm would need to be repeat consumers for them to stay infertile permanently. The only way humans have a hope in hell of winning the long game against rats is to crib one of their rodent foes’ own strategies: strength in numbers.

New York City has pioneered the all-hands-on-deck approach to today’s rat wars. Last year, Mayor Eric Adams made headlines when he appointed the city’s first-ever rat czar (or director of rodent mitigation), Kathleen Corradi. Her job? Overseeing the US$3.5 million set aside for a new rat mitigation zone in Harlem, in addition to minimizing the 44 million pounds of trash NYC generates every day. This past fall, Adams convened more experts, including Himsworth and Byers, to swap tips at a national rat summit. As Adams put it: “We are united in our front to fight Mickey.”

That unity part is key. Rats are what policymakers call a wicked problem, one that has so many interdependent, location-specific factors that a single fix just won’t cut it. If we truly want to get to the root of Canada’s rat issue, our best bets are interventions that are more sweeping and mundane, like better urban infrastructure. If our cities aren’t in great shape, filled with hole-riddled buildings and trash-laden sidewalks, they provide a paradise for rats. “The things that rats need to survive are largely provided by us,” Byers says.

Rat-proofing efforts should start in the sector that unearthed them in the first place: housing. Vancouver, for example, is in the middle of a push to make its buildings more energy-efficient. By plugging up gaps around windows and pipes, rats—who can squeeze themselves through openings the size of a quarter—will have fewer hiding places. Stronger tenant protections will help, too. Rats run rampant in one of Canada’s poorest postal codes, Vancouver’s Downtown Eastside, especially within the area’s rundown single-room occupancy hotels. In one high-profile case from 2017, a city order forced 200 low-income tenants to evacuate the Balmoral Hotel within 10 days. Years of neglect had garnered the building a slew of bylaw violations, including—you guessed it—lots of rats. Bolstering landlord requirements around environmental health, including cleaning and repairs, would do more than raids to keep people-packed urban buildings rat-free.

Our urban waste-management strategies could use an infusion of innovation as well. Some surprising new initiatives are already in play, like backyard fruit-picking programs, which salvage produce and remove rat food sources in one go. As for other trash, last year, a few Toronto councillors called upon the city to test-drive new high-tech bins that use solar power to compact waste, theoretically increasing the average can’s capacity for trash—and keeping it contained. Other cities, including Saint John and Montreal, have tried out a tightly sealed solar-powered receptacle from Bigbelly, which has been put to use around New York. There, Bigbellys reduced rat populations by more than 40 per cent in neighbourhoods—and 90 per cent of parks—where the bins were rolled out.

Lastly, even if an exhaustive rat count isn’t in the cards, we still have to invest in more robust rat-data collection. (As Byers told the CBC, “In some ways, we know more about life on Mars than how rats navigate life on Earth.”) Canada’s cities could take pointers from Seattle, where a sewer-centric program tracks exactly where rats consume bait, helping the city prioritize highly infested neighbourhoods for intervention. In any case, it’s going to require a collective effort. “It is better to invest in brains than birth control,” Himsworth says, “and in people rather than poisons.”

We also need to embrace rat resilience. While we don’t have to love rats, Canadians are probably better off treating them like just another maddeningly clever member of our urban ecosystems, rather than foreign invaders in need of total eradication (which is a pipe dream).They’re easy critters to villainize, but with a shift in perspective, rats offer us an urban Rorschach that can help us grapple with the ways we live in cities—and how we’d benefit from cleaning up our act. I moved apartments a couple of months ago, but, day to day, I still see many familiar sights—namely, rat pancakes and dried-up gore. I’ve come to accept these close encounters, even if I still reflexively watch where I step.