It started with one rat. It scampered across Maggie Kremin’s lawn on a warm summer day and disappeared into her flower beds. Kremin could hardly believe what she was seeing. She convinced herself the rodent was a mouse or a mole, until a neighbour spotted it, too, and pointed out the size and the unmistakable tail, scaly and hairless.

“I didn’t have a clue where it came from,” said Kremin, 66, a devoted gardener with an immaculate backyard in Toronto’s Riverside neighbourhood, near the Don Valley. She has lived there for more than three decades and had never seen a rat before that day in 2016.

That she and her neighbour believed they were dealing with a lone rat makes Kremin laugh now in the sheepish way people do after realizing they’ve underestimated a foe. That first summer, it appeared to be one. The next year brought several sightings and a rising sense of panic. Then came 2018 — or, as Kremin remembers it, the Summer of Rats.

Kremin looked out her kitchen window one afternoon in May and saw a rat on her lawn, which was enough to dash her hopes for a rodent-free summer. Then she watched as two more emerged from her rosebush, like they were gathering for a party.

Kremin and her neighbours mounted a defence, setting traps on their properties. All summer long she shuddered as the traps snapped shut — on one occasion, three times in an afternoon.

“I stopped counting after 25,” she said. “We were overrun.”

She spent the summer afraid to enter her backyard, reluctant to have her nephew’s small children over and terrified the rats would get into her house.

Kremin and a neighbour have been writing to the city since the problem started, asking what can be done about the rats. Her trash and shed are well-secured. Her property is tidy, with no weeds or clutter that could provide harbourage and no loose trash offering sustenance. She feels confident the rats are not coming from her property, and wanted to know what the city could do to help. Baiting in the sewers? Examining nearby alleyways or businesses for infestations?

“Is there an active city program that will be monitoring and controlling the rodent population?” she asked Councillor Paula Fletcher in an email.

The answer was no. The city won’t investigate reports from homeowners about rats on their property or offer advice, except to recommend calling a pest control company.

“I mean, really, does that make any sense to you?” Kremin asks. “The city doesn’t have a program in place to control rats?”

Kremin may call an exterminator if the rats show up again this year, but as a retiree she worries about the cost, which can range from $300 to $1,000 for regular maintenance visits, and she is concerned that taking action on her property alone will not stop the flow. In her view, the city should help identify the source of the problem. Are the rats coming from the sewers? A nearby construction site? An old garage in the laneway behind her house? A restaurant? A neighbour whose fenced-in yard she cannot see?

“They say it’s my responsibility, but I’m just one little part of it,” Kremin said. “The rats are everywhere.”

The urban rat is thriving. Though the problem is difficult to measure because rats are nearly impossible to count, scientists and pest control professionals across North America report that infestations are getting worse.

“I’ve travelled the whole world and everywhere I go the past 10 years it’s off the charts,” said Bobby Corrigan, an urban rodentologist based in New York City whose reputation as one of the world’s leading experts on rodent control has earned him the nickname “Rat Czar.”

In Toronto, rodent-related property standards complaints have doubled since 2012 and pest management professionals say they have seen a steady rise in calls about rats.

“When I first started, it was six months before I saw a rat,” said Brian Evans, a Toronto exterminator who runs BE Pest Control and has been in the business since 1996. “Now I could make my living on them.”

Property standards complaints are highest in neighbourhoods adjacent to the downtown core, where many residents live clustered together in narrow brick century homes and mid-rise apartments that back into laneways, where rats can live large on a diet of improperly stored trash, bird seed, tree fruit and even dog feces.

In East York, residents have reported that brazen rats ignore their traps and even flip them over to remove the threat. A few weeks ago near Bloor and Bathurst, a passerby filmed a video of rats swarming in an alleyway behind several restaurants.

Councillor Ana Bailao reported “a dramatic rise” in rat control complaints from residents and businesses along main streets in west-end Toronto last year, which prompted her April 2018 motion asking city staff to prepare a report on the extent of Toronto’s rat problem and what should be done. The motion passed 39-2, but the report won’t be finished until the end of the year, leaving some residents panicked about another summer of rats.

Kremin and others have been pushing the city to bait in the sewers, but councillors have told residents that city staff say “there is no evidence” this reduces the rat population.

It turns out there is no evidence because the city has not researched whether sewer baiting works or not. “We know from observation and experience that we do not find a significant population of rats in Toronto’s sewers,” a city spokesperson said.

Online community groups are rife with war stories about residents battling rats on their properties:

“They ruined a July 1st (barbecue) by getting at the food on the table when we had our backs turned, and tried to join us for dinner one night while eating in the yard.”

“They swarmed my yard one year when I put down grass seed. It was revolting.”

“They came up and started building a nest under our tub in the basement. They are coming from the sewers and stay behind the walls. My (dog) was going crazy but couldn’t get at them. What a disaster!”

“Ours came in through the basement last fall. Cost $600 to get rid of them and I’m still traumatized to this day.”

“(They) flipped over the rat traps right in front of us. These are smart rats.”

When one homeowner set up a composter in her backyard — “a mistake!” — rats invaded her property and tunnelled into her house through the basement. She found them getting into bread bags in her kitchen.

The stories that seem to cause the most alarm are from residents who have had rats come up through their basement toilets, which people are startled to hear is not an urban myth, but a real thing that happens more often than you want to know. Posts about these morning toilet surprises, which are often accompanied by photographic evidence, inspire panicked comments and vomit emojis.

“Never peeing again,” one commenter wrote.

“If a rat crawled up my toilet,” another said, “I would quit life.”

It’s a wonderful time to be a rat. As cities grow and populations rise, humans produce more trash, and our dumpsters and compost bins give rats the fuel they need to thrive. Construction and demolition, the consequences of gentrification, can disturb underground rat nests, sending rodents scattering into residential areas. Climate change has heated the planet and created more favourable mating conditions, while ageing infrastructure has afforded them more desirable places to burrow.

Wildlife researchers and ecologists often encourage humans to learn to live in peace with the urban animals whose territory we have encroached on — the raccoons and squirrels and skunks among us — but rats are a different beast. The Norway rat common to cities from New York to Vancouver is an invasive species that originated in northern China and has spread to nearly every urban area in the world.

Some believe that if rats had fluffy tails like their squirrel cousins, we would not fret about them. But it is not merely the creepy tails and bad press related to their role in the Bubonic plague that brings them heat. Rats are feared, and for good reason. They can spread disease and infection to humans, including salmonella, rat-bite fever and leptospirosis, a bacterial pathogen transmitted in rat urine that killed a man in New York two years ago. Researchers in Vancouver recently discovered that rats can also carry human-associated pathogens such as MRSA, the antibiotic-resistant superbug, and C. difficile, a spore-forming bacterium known to cause serious gastrointestinal disease.

Rats are also incredibly destructive. They chew through compost bins and car wiring. They gnaw at electrical wires and start house fires. They cause power outages. They tunnel into buildings, leaving trails of contaminated feces and urine in their wake. They can squeeze their flexible bodies through a hole or crack the size of a coin and find their way into a house, destroying infrastructure and the mental stability of the people who live there.

“We’ve been to a lot of homes and you go through and we’re pulling 20 and 30 and 40 rats out of a single home, and see their basement floor caving in because of tunnelling down underneath the concrete,” said Dale Kurt, pest-control giant Orkin Canada’s assistant regional manager for the GTA. “It’s crazy.”

Within a few months, a $500 pest-control bill can turn into a $50,000 basement renovation. What squirrel can do that?

A decade ago in Toronto, “we had almost no calls for rats,” Kurt said. But growth has changed everything. “We see spikes of activity in adjacent areas around where there’s construction,” including a “major displacement of rats” into residential neighbourhoods during the building of the Eglinton LRT.

Rats thrive in part because they are prolific breeders. They reach sexual maturity within weeks of birth. Female rats ovulate every few days and are pregnant for much of their lives, sometimes delivering a dozen babies per litter. National Geographic calculates that it is mathematically possible for a pair of rats to produce 15,000 descendants in a year.

As rats wreak havoc, North American cities have stepped up to tackle the problem with pest management programs, rat patrol officers, demolition bylaws, data collection, scientific research and public education campaigns.

New York launched a $32-million rat extermination campaign two years ago and its public health department runs a Rat Academy for citizens and exterminators. The Vancouver Rat Project, Canada’s first comprehensive study of rats, seeks to understand the risks they pose to human health. Chicago’s Bureau of Rat Control investigates every reported sighting in the city of 2.7 million people, while researchers use big data to manage its infestations.

Alberta, which has gained international attention for being a “rat-free” zone — the province claims to have no breeding population — has a $400,000-a-year prevention budget, a reporting hotline and patrol officers who monitor its border with Saskatchewan.

Some cities are using dry ice to suffocate rats in their burrows. Others have tried using feral cats to hunt them down or drugs to sterilize them, with mixed results.

Toronto has no dedicated rodent control team and no co-ordinated rat strategy. Our efforts on the rat file are siloed. Toronto Water covers the sewers. Toronto Public Health monitors rat-related health concerns and rodent reports in restaurants and public institutions such as daycares and long-term-care homes. The Municipal Licensing and Standards division investigates complaints about unkempt properties that may be providing rodent harbourage. City parks aren’t monitored. Private property owners are on their own.

The city report will explore rat mitigation strategies, public education campaigns and the possibility of new rules that would require developers to prevent rats from scattering into surrounding communities during construction projects.

“People are complaining about big rats in backyards, in streets, in parks,” said Bailao. Residents are “coming to the councillor’s office and saying clearly the rat population is increasing and the city needs to do something about it.

“We can’t just accept that it is homeowner’s responsibility.”

With Toronto facing provincial funding cuts to core public services, it’s easy to dismiss the rat concerns as overblown and argue there are more pressing things to focus on. After all, can a local government really be expected to help every property owner get rid of rats?

“It’s tough for the city to take full responsibility for it, similar to other wildlife,” said Carleton Grant, executive director of Toronto Municipal Licensing and Standards, the department leading the rat study. “People get raccoons, birds, skunks in their attics, under their decks, and it’s not necessarily the city’s responsibility to remove them.

“For the city to take on the responsibility of eradicating rats from every private property would be a huge undertaking.”

But there’s a long way between total eradication, which most cities recognize is not a realistic goal, and no help at all.

The rats are here, whether we like it or not. What should Toronto do about it?

One thing is clear: we need a plan.

“These are public health pests,” said Corrigan, the Rat Czar. “You can’t wait until there’s a disease outbreak and then respond.”

The main reason rats thrive in cities, Corrigan said, is that humans are disorganized — we don’t work together to tackle our problems — “and 20 per cent of us are slobs.”

The favoured method for rat control is Integrated Pest Management, or IPM, which emphasizes preventative measures such as the elimination of food sources and “harbourage” — cluttered or closed-off areas where rats could burrow, including wood piles, tall weeds or junk — while allowing for traditional pest-control tactics such as baiting or trapping.

A Toronto rat mitigation program might include a public education campaign that encourages residents to keep rodents off their property; effective data collection that allows the city to monitor the problem over time; inspectors who investigate complaints on public and private property, especially in neighbourhoods with serious infestations; and rodent control measures, such as identifying and eliminating burrows and using bait stations.

Corrigan doesn’t hold back about the situation we could find ourselves in without a strategic effort.

“If a city doesn’t have a formal structured program to analyze the sewers, the parks, the construction, the alleyways, and people’s backyards, I would say it’s hopeless. Because there’s no poison bait that’s going to bail you out of that ocean of rats.”

How serious is Toronto’s rat problem? It’s a question the city wants to explore with its study, but answers may be elusive.

“The problem right now for most cities in dealing with a rat problem is we have no baseline data to say what the problem was to begin with, if it’s increasing, and where the problem is the most significant,” said Kaylee Byers, a doctoral student at the University of British Columbia with the Vancouver Rat Project.

Don’t bother trying to count every rat, warns the Czar. “I’ve been studying rats for 30 years and I don’t know if there’s two million or eight million” in New York,” Corrigan said.

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More important is knowing if the problem is getting worse, and where.

Complaint data from 311 calls has become the default tracking tool for cities. Chicago and New York record all rat complaints in a central database, whether the sightings occurred on public or private property.

The data has proven useful in combating Chicago’s rat problem. A 2018 study by researchers at the Lincoln Park Zoo and Landmark Pest Management found that Chicago’s rat complaints actually reflect where the most rat activity is happening. It was a surprising finding, since we tend to expect complaints will reflect the likelihood of residents in a particular neighbourhood to complain, rather than the true distribution. The study confirmed Chicago should continue to focus its prevention efforts on high-complaint areas.

The volume of complaints in Chicago — 46,000 from April 2017 to 2018 — has earned it the distinction of the “rattiest city in America,” but it may merely be the most proactive. Some complaints are counted several times — once when they enter the system, and again when they are addressed or followed up on — which may skew the data higher, a City of Chicago spokesperson said.

Another reason for the large volume: Chicago actively encourages residents to register complaints and makes it easy for them to do so by phone or with a smartphone app. And complaints come with the promise of help, since the city investigates every reported rat sighting.

Complaint data provided by the City of Toronto seems mild in comparison. Toronto had 924 rodent complaints across the city last year, up from 361 a decade ago, but these numbers only reflect a narrow category of complaints: those made to municipal licensing and standards about unkempt properties, where the word “rodent” is mentioned.

Unlike Chicago and New York, Toronto does not collect data from private property owners reporting concerns about sightings in their yards.

“I called 311 today to tell them about my rat sightings in my backyard and they … told me there is not a ‘Rat Complaint Process’ and there is nothing they can do,” one resident wrote in an online group.

If Maggie Kremin lived in Chicago, her 311 call would trigger an investigation. Rat control officers would visit her neighbourhood and bait in the alleyways adjacent to her home. They would search for burrows and collapse them. They would look for food sources, such as overflowing dumpsters or trash bins, and work with residents and business owners to eliminate them. With Kremin’s permission, they would inspect her property, inside and out, and offer advice on how to keep rats away.

If Kremin’s street or neighbourhood became a hotbed for complaints, the Chicago rodent control officers would schedule a “blitz,” going door to door in her community to assess the area in one planned attack, identifying rat burrows and treating them with rodenticide.

Chicago’s Bureau of Rat Control might advise residents to remove birdseed, cut back weeds, repair foundations and rid yards of dog poop, a protein-rich food source that Chicago researchers have learned is a huge draw for rats: the areas with the most rat activity also have the most poop.

If residents can’t afford to hire a private company to rid their property of rats, the city takes care of it.

Kaylee Byers of the Vancouver Rat Project sees rat control as a social justice issue. Byers has studied how living with rats has affected people on Vancouver’s Downtown East Side, where many residents face precarious housing and homelessness. She said it is important to consider the mental health impact rats have on the people forced to live with them, rather than focusing solely on the potential for disease transmission.

In her study, Byers found what you might expect: “People were afraid of rats.” They associated them with the plague. They were fearful of being bitten, fearful of getting sick. “Rats seemed to particularly affect people when they lived in their home, making sounds in the walls, or when they were homeless.”

For people living with rats, “a lack of action from those deemed responsible represents social injustice,” Byers said.

Another recent move in Chicago’s war on rats is that developers are required to have a rodent control management plan for construction or excavation projects, to prevent the displacement of rats into neighbouring communities. There is no such bylaw in Toronto, even though residents and pest management professionals have reported spikes in rat calls from residential neighbourhoods near construction projects.

Toronto will look at mitigation efforts in other cities as part of its study, said Carleton Grant, head of municipal licensing and standards.

When asked, half-jokingly, if his department would try counting the rats, Grant sounded weary. And who can blame him?

“We have a very small policy team here, and we’re working on literally hundreds of directives from council on a variety of issues,” he said. “We do not have experts in this area or a huge research component that we can put towards this.

“We’ll do the best we can to give committee and council enough information for them to debate this and to make decisions to move the city forward.

“As we do with all our work, we really try to learn from other cities but come up with a Toronto-own solution.”

Humans have a curious tendency to ignore distressing problems. Maybe you spot a rat slipping under your deck, but you convince yourself it couldn’t have been a rat, or that it was just one rat passing through, and everything is fine, just fine.

Ignoring rats is a bad idea.

“Some people turn a blind eye to it,” said Dale Kurt with Orkin Canada, the pest control company. “Some people think they can do it themselves, and they’ll try buying a couple of traps from the hardware store. But keeping in mind how quickly they can reproduce, if they don’t get success very quickly, suddenly they’ve got a bigger and bigger problem.

“If you do notice a couple of droppings in the garage, you want to act on it quickly. Because it doesn’t take long.”

A single pregnant rat can turn into 10 or more baby rats before you know it.

“So if you think, ‘I’ve got a few droppings in the garage but it’s not a big deal.’ Well, in a month and a half it’ll be a really big deal, right? Suddenly they find a way into the house, through some kind of gap or crack. Then it’s a totally different situation. When you’re sharing your home with a rat, it’s not a good feeling.

“I don’t want to say people can’t get rid of rats by themselves but it’s difficult,” Kurt said. Mice are easier for the handy homeowner to eradicate. But rats can become trap-shy, ignoring bait while continuing to multiply and cause destruction. “It’s very, very hard. Even for trained technicians it can be very hard.”

Homeowners must do their part, but the city needs to get serious about tackling the rat problem, Kurt said.

“The longer you look at it and make plans, the more rats are reproducing out there.”

HOW TO PROTECT YOUR HOME FROM RATS

Eliminating food

Make sure green bins or garbage have tight lids, no holes chewed in them

Clean up fruit that falls from trees, on a daily basis

Backyard composters should be removed if there are rat concerns in your area

Vegetable gardens draw rats; use with caution

Eliminate spillage from bird feeders, or don’t have them at all

Do not leave pet food or water outside

Grass seed draws rats; use with caution

Dog feces should be picked up immediately

Eliminate water sources

Eliminating ‘harbourage’ or shelter

Trim long grass, shrubs or vegetation as short as possible

Remove clutter, such as junk or wood piles

Fill any gaps or cracks in the foundation of your home or around pipes

Seal any possible entrances to your garage, including gaps under doors

Do not leave windows or doors open

Cover the dryer vents

Watch for signs of rat activity: droppings, gnaw marks or grease stains

Clarification, June 6, 2019: This article was updated from a previous version that suggested rats have a mating season. Rats mate all year, but more in warmer months.