Boston still considers its Ward 3 area to be the highest priority neighborhoods for rodent population management efforts.
Defined as Downtown, Chinatown, North End, South End and Haymarket, the Ward 3 area was determined to be the most in need of rodent intervention by a 2024 study that analyzed 311 complaints, Inspectional Service Department (ISD) violations, input from city inspectors and neighborhood surveys.
However, John Ulrich, the assistant commissioner at the ISD who oversees the agency’s implementation of rodent control recommendations, said that it’s impossible to gather a single picture of rodent populations across the city.
Because rodents are not geographically confined to the clean neighborhood boundaries that city officials use, and 311 data provides a useful but incomplete picture of actual population numbers, the city can only determine areas where increased population control methods are recommended.
Following Ward 3, the city considers the next highest priority neighborhoods to be Allston/Brighton, Back Bay/Beacon Hill and South Dorchester/Roxbury.
The report also found evidence of rodent activity throughout the city, describing rats as present in “most, if not all,” Boston neighborhoods.
While 311 complaints related to rodent activity have risen steadily over the last five years, from 3,636 reports in 2021 to 5,957 in 2025, the city has made an effort to urge residents to use the 311 system more and increased its responsiveness to those reports.
Ulrich said the ISD currently has 14 inspectors working daily to respond to 311 complaints within 48 hours, and that the department has completed 150 neighborhood walkthroughs since the 2024 study. Inspectors also work with neighborhood groups and property owners on containerizing trash and reducing food waste, the biggest mitigating factors that the public can manage to reduce rodent populations.
Since the 2024 study, the city has installed more rodent-resistant trash receptacles in parks and public places and is incorporating rodent-resistant plans into new infrastructure.
The Boston Rodent Action Plan strategy that resulted from the study emphasizes eliminating the conditions that allow rats to thrive before resorting to rodenticide and extermination.
Ulrich said Boston has stopped using second-generation anticoagulant rodenticides on the surface of city property, which are more harmful to non-target animals, and is instead relying more heavily on carbon monoxide and carbon dioxide treatments for burrows.
The shift in rodenticide policy has brought down the usage of the types of poison that were responsible for the death of a bald eagle that was nesting in Arlington, Massachusetts earlier this year and was suspected in the death of another bald eagle in the area in 2023.
The city is also experimenting with new technology to better measure rodent activity, including heat sensors inside bait boxes and artificial intelligence designed to analyze rat vocalizations.
Luke Hines, a representative for the Mayor’s Office, said results of such studies are too early to be definitive, but the data will be useful in determining whether population control interventions are working.
