Study Finds Urban Rodents Rapidly Outsmart Poison and Traps

A new Rutgers University study says city rodents are evolving quickly to survive human efforts to eliminate them. The research, reported Thursday by the New York Post, found that about 70% of house mice now carry a genetic mutation that makes common rodenticides ineffective, while rats are developing unusual intelligence that helps them evade even sophisticated traps.

Postdoctoral researcher Dr. Jin-Jiao Yu of Rutgers’ entomology department said the animals have adapted to human strategies and that people must become “a lot smarter” than they are. Yu and his research partner, Changle Wang, sampled DNA from 300 house mice and Norway rats in dense urban areas in New York, New Jersey, Pennsylvania and Washington, D.C. The team said the two species are evolving rapidly, but in different ways.

According to the study, the mouse mutation neutralizes anticoagulant poisons, the most common form of chemical pest control. Wang said that when mice eat the poison, “the body continues to function normally,” because they have developed resistance after decades of repeated exposure to unfamiliar food sources, including bait.

Rats, by contrast, did not develop the same mutation as quickly, but recordings from the Bronx showed them becoming expert escape artists. Yu said videos show rats avoiding spring traps and glue traps, and that they can make “300 different approaches” around a trap over a week before touching it. The researchers warned that continued reliance on poison could harm urban wildlife such as birds, coyotes and other scavengers that eat contaminated rodents, and they urged city leaders to move away from chemical control toward prevention, sealing entry points and stricter sanitation.