Full Breakdown
Rising Rat Populations Linked to Global Heating and Shifting Control Strategies
8/25/2026, 9:56:50 PM
Rising Numbers in a Warming World
A 2025 study led by Dr Robert Corrigan and ten co-authors examined rat counts in 16 cities worldwide. The researchers reported a dramatic rise in both black and brown rat populations and identified a correlation between higher ambient temperatures and increased breeding cycles.
Study Findings and Public-Health Concerns
The authors highlighted that rats can transmit Weil’s disease, hantavirus and emerging coronavirus variants.
Emerging Non-Poison Approaches
Several experts are promoting fertility-control technologies as a humane alternative. Richard Parr, director of the UK charity the Center for Wild Animal Welfare, argues that “developing new forms of birth control is the key to managing the soaring number of poison-resistant rats compassionately.” The EU’s current biocidal regulations, however, are described as “stifling innovation,” delaying wider adoption.
Alberta’s Long-Term Eradication Model
Karen Wickerson, the province’s rat and pest specialist, attributes this success to a coordinated program launched in 1950 that combined mandatory reporting legislation, public-education campaigns, and targeted use of anticoagulants and traps. Recent warm autumns and increased tourism pose new challenges, but the provincial framework continues to emphasize prevention over chemical reliance.
Key Voices
Official Statements & Responses
- Dr Robert Corrigan emphasizes that rats are “smart mammals with mammal brains” and critiques the “band-aid” nature of widespread poison use.
- Richard Parr stresses the promise of contraceptive technologies while noting regulatory hurdles in the EU.
- Karen Wickerson points to collective citizen action and historic rat-patrol efforts as central to Alberta’s low infestation rates.
Verbatim Quotes
- “The rodents have paid for every single bill I’ve ever had – every mortgage, every car payment, every pint of Guinness,” — Dr Robert Corrigan
- “Developing new forms of birth control is the key to managing the soaring number of poison-resistant rats compassionately,” — Richard Parr, director of UK charity the Center for Wild Animal Welfare
- “There was a rat patrol that went out and started eradicating all the infestations along the border. At that time there were probably six or seven hundred infestations a year,” — Wickerson. In
