Urban Mice and Rats Show Anticoagulant Resistance

A significant portion of urban rodents in the northeastern United States are carrying genetic mutations linked to resistance against common poisons, according to a new scientific study, raising concerns about the effectiveness of long-standing pest control methods and public health risks. The research, led by Rutgers University and published in the journal Pest Management Science earlier this year, analyzed DNA from 147 house mice and 143 Norway rats collected in urban areas of New York, New Jersey, Pennsylvania, and Washington, D.C.

The findings revealed that 84 percent of the house mice carried at least one mutation in the Vkorc1 gene, which is associated with survival against anticoagulant rodenticides. Nearly 70 percent of the mice had mutations already known to help them survive these common poisons. Among the Norway rats, about 35 percent also carried mutations in the same gene, though researchers noted it is not yet clear if those specific mutations directly reduce the rats' vulnerability to the chemicals.

Study author Changlu Wang, an extension specialist in entomology at Rutgers University, stated that the high prevalence of resistance in mice is a result of repeated...