Mutant mice resistant to pest control found in Philly, its suburbs, and NYC. Are rats next?

Key Points:

• A Rutgers University study found that house mice in Philadelphia, Trenton, and nearby suburbs carry genetic mutations that confer resistance to common rodenticides, indicating evolving survival against chemical baits.
• The majority of house mice sampled from Northeast urban areas, including New York City boroughs, had at least one mutation linked to rodenticide resistance, while Norway rats showed fewer mutations but may evade traps through learned behavior.
• The research highlights a growing challenge for pest control companies, suggesting the need for new strategies to manage rodents that are either genetically resistant or behaviorally adept at avoiding capture.
• The study analyzed DNA from 147 house mice and 143 Norway rats across several cities, finding 84% of mice carried VKORC1 gene mutations related to rodenticide resistance, whereas about 35% of rats had mutations whose impact is still unclear.
• Urban areas report higher rodent sightings, with Philadelphia showing a 29% household sighting rate, emphasizing the significance of effective rodent control in metropolitan environments where resistance and behavioral adaptations complicate eradication efforts.