Carlos Solis
Common rodent poisons may not work as well as they used to. A new study found that a large share of house mice and a sizable portion of urban rats carry genetic mutations linked to resistance to anticoagulant rodenticides.
How the analysis was done
Researchers at Rutgers University sequenced DNA from 147 house mice and 143 urban rats. They searched for mutations in the Vkorc1 gene, which has long been associated with resistance to anticoagulant rodenticides—the most common rodent poisons used in the U.S.
- About 70 percent of the mice studied had mutations linked to surviving exposure to those poisons.
- About 35 percent of the rats had mutations in the same gene.
Why researchers looked into it
Pest-control workers had been reporting rodent populations that wouldn’t disappear after rodenticides that used to work were applied. Those reports prompted the study.
Coauthor Changlu Wang says rodents aren’t just a nuisance—they also pose a public health threat. He says that as resistance cases rise, it becomes more important to use science-based control methods that protect people and the environment.
The authors emphasize that studies like this help us understand how rodent populations are changing and how control strategies need to adapt.
This report draws on BBC Science Focus reporting.
