Rodenticide Replacement Program
A five-year, $30M coordinated research program to tackle rodent fertility control.
Developed through the BiTS program, part of Renaissance Philanthropy. Interested parties can reach Mal Graham at mal.graham@renphil.org.
The problem
Globally, rodents cause major economic, public health, and conservation damage.
Why rodenticides don’t solve it
These problems persist despite widespread rodenticide use because of two forces: immigration — rodents from adjacent areas move into cleared ground — and compensatory survival — smaller populations mean more resources per animal, so more juveniles survive. The result is rapid rebound. In a recent field experiment, rodenticide plus intensive trapping cut multimammate mouse populations by 74–92%, and populations returned to pre-treatment levels within six months.
Worse, the migration rodenticides provoke accelerates disease spread. In Vancouver, lethal rat control was associated with a nearly tenfold increase in the odds that surviving rats carried leptospirosis.
Preventing rebound would require treating every connected patch of suitable habitat, repeatedly, at once. No available rodenticide is safe enough to use that way:
Direct threats to human health. Metal phosphides are common in low- and middle-income countries, where SGAR access is limited and illegal sales are extensive. They work by producing phosphine gas — deadly to humans, pets and livestock, with no antidote. In India, 54% of ingestions are fatal, likely causing thousands to tens of thousands of deaths a year.
Harms to wildlife. Second-generation anticoagulants linger in rodents and poison the animals that eat them, undermining natural rodent control. Despite restrictions, clinically significant exposure has been found across non-target wildlife — rodenticides appear in the livers of 82% of bald eagles and 95% of cougars tested in the US.
The solution
The program funds a portfolio of approaches to alternatives that are safe to apply at scale — effective population control without the externalities. Fertility control is the best bet, for two reasons. The lab rat is a domesticated brown rat, one of the most problematic species, which means nearly every compound explored for human contraception has already been tested in our target animal. And developments in human vaccine delivery, plus self-spreading rabies vaccination in wildlife, are directly relevant to species-specific immunocontraceptives.
A complete solution has three parts, and no team today holds all three.
Precedent exists: contraceptives already manage pigeons, horses and elephants, and aerial rabies vaccination of wildlife has been extraordinarily successful. Even short of outperforming rodenticides everywhere, fertility control would complement them — reaching bait-shy individuals and giving a safe option for areas with children, refugees and other vulnerable populations.
Why now
The demand signal is already here. California and British Columbia have banned some classes of rodenticide, other US jurisdictions are contemplating ending the exemptions that let rodenticides bypass normal pesticide rules, and most strikingly the EU has designated SGARs as “candidates for substitution” — meaning that once a safe and effective alternative exists, they will no longer be approved.
Nobody is positioned to supply that alternative. One company has sold rodent fertility control products in the US since 2016, but they are widely considered ineffective and insufficiently tested. A hormonal product is in use in China and Tanzania, but EU and US regulators have signalled they will not approve environmental administration of hormone-based products. The rodenticide industry itself is not pursuing fertility control: contacts say they would adopt and produce an effective product, but are averse to funding the R&D.
Meanwhile the research community is systematically underfunded — too applied for NSF, too distant from human health for NIH, too early for commercial investment — and the relevant innovations sit in widely separated disciplines, from food science to vaccine delivery. Without coordinated investment, the emerging bans will push rodent control backward toward historical options rather than forward.
Our approach
We are seeking $30 million to advance a portfolio of approaches targeting landscape delivery of rodent contraception. Philanthropic investment supports parallel exploration of multiple delivery–cargo combinations, so funding can concentrate on the options that show the most potential.
Candidate compounds are tested in the lab for effectiveness, safety and specificity; survivors move to controlled field settings, with a target of advancing two to three compound–delivery pairings into field efficacy trials by month 36. To break the siloing that has slowed this field for decades, the program opens with a six-month matchmaking process that forces integration across reproductive biology, vaccine engineering, formulation chemistry, animal behaviour and field logistics.
These five are responsible for the vast majority of agricultural, conservation and human health damage worldwide.
Draft structure, to be refined with our technical advisors.
Our team
The team pairs fertility control domain expertise with deep operational experience in conservation and scientific program management. Our technical advisors bring a combined 90 years of rodent management and fertility control experience.
Broader impacts
As habitat is replaced by human-modified landscapes, people and animals are increasingly in conflict over space and food, while attitudes turn against lethal management — which is neither always effective nor usable everywhere. A robust fertility control research community is infrastructure we will need regardless.
Advances in vaccine delivery should translate into wildlife health more broadly, with implications for human health. Where a human vaccine is impossible or too expensive, vaccinating animals can be the most tractable path — oral rabies vaccination is the proof of concept, and similar approaches are being explored for Lyme disease, leptospirosis and bovine tuberculosis.
The program also builds durable scientific infrastructure. Matchmaking and multi-year collaboration create lasting links between reproductive biology, vaccine engineering, wildlife ecology and delivery chemistry — communities that currently operate in isolation. Even compounds that fail our criteria may leave behind tools, methods and trained researchers.
Get involved
If you’re a funder considering this program, or a scientist who could contribute to one of the paired teams, we’d like to hear from you.