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Can Vancouver Use Birth Control to Control Rat Infestations?

Can Vancouver Use Birth Control to Control Rat Infestations?
Can Vancouver Use Birth Control to Control Rat Infestations?

Other North American cities also consider the approach successful.

Vancouver continues to face a rampant rat infestation in the city. The rodents can grow in staggering numbers, with females capable of producing litters of 12 young every three weeks, meaning a rat pair can produce up to 2,000 offspring annually.

Other Canadian cities are now considering creative ways to control the growing numbers of rodents.

Ottawa City Council recently unanimously supported a motion asking Health Canada to review fertility controls in rats (rodent birth control).

The motion also emphasizes that deadly rat poisons cannot be effective because the rodents learn which products to avoid.

College Board member Laine Johnson, who introduced the unique motion, wrote in a post on X, formerly Twitter, that rat birth control has a 99 percent success rate, making it a viable alternative to pest control.

Many advocates say it is also a more humane way to address the city’s growing pest problem, as there is no pest control involved.

Vancouver residents are seeing rat infestations across the city

Vancouver residents have shared several videos on social media of rats running in packs through busy pedestrian areas, community gardens and restaurants. Many believe the rat population has exploded, with experts reporting an increase in the number of rodents.

Westside Pest Control President Mike Londry told VIA that his company saw an increase in mouse-related calls in 2023, a staggering 100 percent increase. He also received more rat calls, but said they tapered off later in the year.

Londry and many of his pest control colleagues say British Columbia’s ban on second-generation anticoagulants (SGARs) has played a role in the rodent population boom.

The Vancouver Board of Parks and Recreation says it has not seen an increase in rat numbers since the ban was implemented in 2020. The board says rodent management focuses on prevention and exclusion.

“Exclusion measures are aimed at preventing rats from entering buildings, such as sealing holes, installing mosquito nets and door sweeps under doors,” a statement to VIA said.

“The Park Board does not use contraceptives for rat control as there are no registered rodent contraceptives in Canada.”

The City of Vancouver also offers residents and developers educational materials on how to reduce the likelihood of rats taking up residence, and teaches how to prevent rats from taking up residence by keeping your property clean and well maintained.

City staff keep track of rat reports, and in 2023, 1,174 problems were reported to the city through 311.

Vancouver rat expert gives his opinion on rodent management

Public health scientist Dr. Kaylee Byers has worked closely with rats for more than a decade and was involved in the first comprehensive rat study in Canada.

The Vancouver Rat Project was founded in 2010 by Dr. Chelsea Himsworth to learn more about the rat population in Vancouver’s Downtown Eastside, including the diseases they carry and their behaviour.

Byers and the team captured rats, tagged their ears, and collected urine, blood, and fecal samples.

The team found that the diseases rats carry vary greatly between city blocks, because most rats don’t move far. A “happy” rat—one that has all of its needs met, including a food source, water, a place to dig, and access to mates—has no incentive to move… and they don’t.

For example, in the DTES, one city block may have multiple diseases in each rat, while the rodents in the block next door may be relatively disease-free.

According to the rat expert, poison can be effective in some cases in controlling indoor rodents, but it can do more harm than good.

In an outdoor environment, rat poison can pose a risk to the environment because animals that eat rats, such as cats and coyotes, ingest it. Likewise, poison can end up in water.

Rat-based birth control proves successful in major US cities

Ottawa’s latest motion notes that products used to reduce rat fertility have been deemed “successful” in other major cities, including San Francisco and Washington, D.C., and that they are being tested in New York and pose no risk to other animals.

While Byers isn’t particularly familiar with Evolve Soft Bait, she said the city should consider rat behavior when implementing it. She mentions how she has sometimes placed bait near a large garbage can where rats would gather and they would ignore it. They are also neophobic, meaning they are afraid of new things in their environment.

“It also depends on how often rats have to eat the bait for it to be effective. Some human contraceptives require it to be taken daily. If rats have to eat bait daily, that’s probably not going to happen,” she told VIA

Byers also notes that bait works best in enclosed, indoor environments. The program can also take longer, but is more humane than poison.

“We need to think carefully about the positive and negative consequences,” she says.

Ottawa City Councillors also stressed that Ottawa’s rat population has increased due to factors such as climate change, habitat loss and construction.

Despite years of studying rats, Byers says no one knows Vancouver’s population numbers, but it’s important to include rodent control in city plans. Their populations can grow alongside humans, which can have serious health implications.

“When we design rat management programs, we need to take a holistic approach. Not just one problem (and) more than one tool in a toolbox,” she notes.