Efforts are being made to combat the increasing numbers of rats in two of Ontario's largest cities, as rodents that usually lie underground have become more visible due to a mix of construction and climate change.

In Toronto, the municipal infrastructure committee recently adopted a proposal asking the city council to direct staff to draft a "action plan" to reduce rats in the city.

The proposal put forward by Alejandra Bravo and Deputy Mayor Amber Morley is a response to residents' concerns about the rising number of visible rats in local neighborhoods.

Bravo said, "People were talking about this in 2022 as a growing problem, and over the past year and a half... it has been escalating and growing," noting that residents in her neighborhood found themselves "overrun" by rodents.

"It's really a critical issue regarding quality of life when people suddenly encounter rats entering their homes or workplaces... a combination of factors has come together to create this kind of perfect rat storm."

Bravo noted that the sharp increase in construction in the city, driven by transit projects and housing development, has disturbed rat habitats deep underground, pushing them into open spaces where they can be seen by people.

She added that longer periods of warm weather due to climate change have also enabled rodent populations to thrive by extending breeding periods.

"We've been helped by the cold winters because that led to a halt in rat reproduction. But since winters are not cold enough, it means rats can breed every two months."

The proposal by Bravo and Morley - which will go to the city council for a vote later this month - seeks to urge the council to ask the city manager to consult with other communities in North America on their approaches to reducing rats.

In Ottawa, the city is exploring a form of rat birth control that is not yet legal in Canada.

The local council recently supported a proposal put forth by Lain Jonathan, asking the Canadian Ministry of Health to expedite the review of a product called ContraPest, which has already been rolled out in Seattle.

ContraPest works by promoting early menopause in female rats while reducing sperm production in males.

Johnson described it as a better solution than rat poison because rats have the ability to "know" harmful food sources and alter their behavior.

A trial of oral contraception was conducted in Washington, D.C. in 2019, but the health department stated that "the results proved inconclusive" and ceased use of the product.

Meanwhile, Alberta says it has been a rat-free area for about 70 years, committing to a zero-tolerance policy that even prohibits residents from keeping rodents as pets.

The province added that it does not allow rat populations to establish, and while there may be occasional minor incursions, those rats are isolated and eliminated when found, emphasizing that public vigilance and preventing rat outbreaks through efforts like rat-resistant structures and removing food sources is essential.

Karen Wickersham, a rodent and pest specialist in the province, questions whether the humane birth control strategy proposed by Ottawa will be sufficient to combat the problem facing North American cities alone.

She said, "They have to continuously eat (the birth control) for it to continue (reducing the population), so I think there are a lot of things missing in this strategy."

Wickersham has led the province's rat control program for four years and says that a multi-faceted approach is essential, but ultimately the province enforces a rat eradication strategy based on reports from vigilant citizens.

Wickersham stated that the program, which began in the 1950s, has been so successful that many Alberta residents no longer even know what a rat looks like, and sometimes send pictures of tree squirrels to the government’s official email.

She added, "If you’ve never lived outside of Alberta, you may have never seen a rat before, which is why it’s often misidentified," adding that the muskrat accounts for about 50 percent of the annual reports ranging from 400 to 500 about alleged rat sightings. 

Alongside public education and engagement, Alberta has created a real rat ban area. The Rocky Mountains to the west and coordination with neighboring Saskatchewan to the east have fortified the rat-free border, which could be difficult to establish in urban centers in Ontario.

Johnson, a member of the Ottawa Council, said, "For the province of Ontario, that rat is out of the gate. So unfortunately we have to work reactively instead of proactively like Alberta was able to support 70 years ago."

Ontario is not alone in battling rats 

New York City's mayor is set to host an urban rat summit in September, with expected participation from experts from cities like Boston, New Orleans, and Seattle.

The inaugural conference aims to bring together pest control experts, academic researchers, and politicians to share best practices for combating rat populations in North American cities.

Bravo, a Toronto Council member, said that knowledge sharing and coordination across regions is key in the battle.

Adding, "We are part of a massive, ongoing city here, and collaboration is always important. If there are good measures being taken in Peel or in Ottawa or in Chicago, we want to know about it."