Rats are constantly talking to each other. Boston is using AI to eavesdrop

Boston has partnered with the nonprofit Basis Research Institute to deploy AI-powered ultrasonic microphones that detect and decode rat vocalizations, with Basis recording over 10,000 vocalizations per night and more than 1.2 million rat calls collected so far across Boston and New York. Basis scientist Ralph Peterson said the team is training models to extract when vocalizations occur and when rats are in frame, building a rat "dictionary" that could help the city map where rats are, where they will go next, and whether deterrent efforts are working. The research-focused partnership costs taxpayers nothing and is in the data collection phase with no set end date, and was demonstrated at Boston's second-annual National Urban Rat Summit.

Support WBUR Rats are constantly talking to each other. In Boston, scientists are using AI to eavesdrop The city of Boston is partnering with an artificial intelligence-powered research group to help cut down on the urban rodent population. The tech, on display at the city's second-annual National Urban Rat Summit last week, is part of an arsenal of tools the city is employing to cut down on the rat population. The disease-carrying vermin https://www.wbur.org/npr/nx-s1-5584119/rats-birth-control-rodents pose a health threat to humans and have a propensity for property destruction https://www.wbur.org/news/2024/03/28/rats-boston-massachusetts-infestation-trash-prevention , making them a key target for the city. The high-tech tool from nonprofit AI organization Basis Research Institute https://www.basis.ai/projects/collaborative-intelligent-systems/rats-faq/ works to detect and decode what exactly rats are saying to each other, just outside the range of human hearing. “It's as if there's a bird dawn chorus happening all night,” said Ralph Peterson, a scientist Basis, “but we would never know because we can't hear it.” By mapping their vocal repertoire and building a rat "dictionary," Peterson and his team could help the city map where rats are, where they’ll go next and determine whether deterrent efforts are working. Over the last six months, they've installed gray, toaster-sized ultrasonic microphones to pick up rat calls in half a dozen spots around the city. The partnership comes at no cost to taxpayers, because the work is research-focused. The project is currently in the data collection phase, with no set end date. In a single night, Basis can record over 10,000 vocalizations. “ There's a mating call. There's an alarm type of call," Peterson said. Those are often too high for humans to hear. "There's a kind of aggressive squeak that you might have heard at night." Altogether, Peterson’s team has so far collected more than 1.2 million rat calls between Boston and New York. It would take an enormous amount of time for a human to listen to all the vocalizations and match sounds to behaviors captured on separate thermal video cameras, but artificial intelligence is helping. “We’re using AI to go in and do that analysis for us,” he said. “So we train these models to go into our audio and extract out when vocalizations occur, or when rats are in frame.” 'Rat walk' demonstration The public got a glimpse of the partnership between Boston and Basis at the city's National Urban Rat Summit. The conference brought together people from around the country to talk solutions to the pesky problem. Among the summit's unique offerings was a “rat walk,” showing attendees the different ways the city is trying to intervene in their varmint sprawl. On the chilly nighttime walk, a group of Boston officials, rat mitigation experts and rodent enthusiasts crowded around shrubbery in the Public Garden to spot a rat. On the rumor that one was near, flashlights appeared, beams searching for the critter. One woman lay on her stomach to get a better look. Finally, Ricky Meinke, of Allston, caught sight of a rat skittering beneath the leaves. “There he goes,” said Meinke, who organizes the annual Rat City Arts Festival https://www.wbur.org/news/2026/07/30/rat-city-arts-festival-allston-newsletter . “Little crawler. He’s got muscle.” Meinke, dressed in an Indiana Jones-inspired "Rat Ranger" costume, said he's skeptical of the AI tech. "Is it like the rat Flock cameras?" he asked, referencing the controversial license plate reader technology https://www.wbur.org/news/2026/09/14/flock-boston-police-pilot-surveillance-technology-report . "The headline, I think, is always going to garner attention, but then you think of the actual project management of the headline itself, and that is where it could be really tough in the long term and we might not actually see it be a success or a long term use to address rats." The Basis team said they're aware that audio surveillance of rats raises questions about human privacy, so their models are trained to automatically detect and extract human speech. " This microphone is hot," said Basis scientist Nick Jourjine told walk participants. "It's picking up all the speech that's happening here, but our pipeline, once we upload this data, will detect that speech and remove it from the audio so that we can safely record rat vocalizations at scale without putting the people in the communities that we're trying to help at risk of having their personal conversations recorded." Another rat walk participant, Kim Kammerer came to Boston from South Carolina for the summit. She runs an extermination company and often relies on old school methods: dogs and ferrets to find and kill rats. But she said she supports the new technology. "I don't think we should leave anything off the table," she said. "I think it scares people. They're thinking jobs, will they do away with jobs? But you still need a good pest control company, you still need a good technician." New tool, old problem It’s all very exciting for John Ulrich, Boston’s assistant commissioner of environmental services, or, more simply, the guy you call when you’ve got a rat. In his 23 years working for the city, the Southie native has learned how hard it is to eliminate rats — let alone count them or collect data on what's working. A previous AI experiment in Boston by a startup failed because of staffing problems, he said. But his hopes remain high. Ulrich wonders if there’s a world where city officials could talk to the rats directly. "If there was something that we could then play back to them to alter their behavior," he said, trailing off. "I mean, that's my wish." Until then, he'll stay sharing old school rat control advice: keep yards and alleys clutter-free, call 311 if you see a rodent, and put your trash away properly. This segment aired on September 29, 2026.