Boston won’t implement rat birth control yet after pilot results

City officials said pilot program in Jamaica Plain didn't prove effective, but a nonprofit said there were fewer rats around Hyde Park.

Rat birth control won’t be coming to Boston any time soon after a pilot program in Jamaica Plain didn’t necessarily prove effective, city officials told the Boston City Council this week.

Tania Del Rio, the commissioner of inspectional services, told councilors Monday that there wasn’t a decrease in 311 reports of rats during the pilot. In JP, there were 82 complaints in 2023 and 154 so far this year. At the precinct level, while it was a small subset, there was an upward trend of reports.

“Since the product is still in the research and development phase, we have been observing, monitoring it, because if it proves effective, it is something we should definitely adopt,” Del Rio said. “At the same time, we want to be good stewards of taxpayer money, and if it’s still in that research and development phase, we don’t want to be the kind of people experimenting on it if we’ve received mixed reports.”

Wisdom Good Works conducted the rat birth control pilot at residential buildings in a two-block area of Hyde Square between August 2023 and 2024, the nonprofit’s Director of Operations Alaina Gonzalez-White told councilors. Their results told a different story, she said.

They monitored an increase in the rats eating the plant-based solid feed pellets, which make the rats infertile, but don’t endanger their predators, pets, or humans. Their findings, using consumption levels of the feed decreasing and cameras, reported a rat decline of 50 to 70 percent, depending on the month.

“The residents of Jamaica Plain have demonstrated this success to show an important first step has been taken in ridding Massachusetts of harmful poisons and repeated half measures,” Gonzalez-White said. “Fertility control is a proactive approach that is a 21st century solution to an age-old problem.”

John Ulrich, the assistant commissioner of environmental services, said some neighbors saw an increase in activity, including at a few community gardens. He said “the data basically is based on consumption.”

“The challenge is open populations, and how do we deal with that? I think Dr. Mayer can prove that her product works, but how do we use it in a city with an open population, in a neighborhood like JP or a neighborhood like Brighton? What is the best strategy, and what other tools can we use with that product to make sure it’s successful?” he said.

Del Rio said the department wants to learn more about the cameras Wisdom Good Works used. But while 311 reports are an “imperfect” proxy for population counts, Del Rio said, Boston’s Inspectional Services Department won’t pursue rat birth control “at the moment” due to those findings.

D.C. tried rat birth control, NYC poised to begin

Earlier this year, Boston Mayor Michelle Wu announced the Boston Rodent Action Plan, an initiative to decrease the rat population across Boston by improving waste management. The action plan, in part prepared by national urban rodentologist expert Bobby Corrigan, didn’t explore birth control for rats.

In 2019, Washington D.C. trialed ContraPest, which was invented by the founders of Wisdom Good Works, Loretta Mayer and Cheryl Dyer.

During the trial, the company found that rat sightings decreased by 90 percent, based on camera data. However, D.C.’s Department of Health decided to not continue the product “after the results proved inconclusive.”

Officials in New York City greenlit a pilot program to use ContraPest just last week. Their move comes a year after Kathleen Corradi was named the city’s first “rat czar” to mitigate the pests in Harlem.

Why some cities want to avoid rat poison

Councilors ordered the hearing in July to discuss rodent birth control following incidents of children, cats, dogs, owls, and a local bald eagle named MK being harmed or dying from anticoagulant rat poisons.

MK, one of the at least four bald eagles in Massachusetts to die from second-generation anticoagulant rodenticides, was found in Arlington, which prompted a ban on town property last year.

The animal welfare activists at the hearing, including veterinarians, Mass Audubon, the MSPCA, an animal welfare lawyer, and the New England Wildlife Centers, told councilors about the harms of anticoagulant rodenticides and emphasized a need for humane alternatives. Each mentioned rodent birth control.

Martha Smith-Blackmore, a veterinarian who works with the city’s animal care facility in Roslindale, said out of nearly 200 hawks, falcons, and owls brought to city shelters for care since 2019, only 20 percent were strong enough to be transferred to a hospital.

“Some, of course, are injured hit by cars or electrocuted by power lines, but some of the injured birds get injured because they’re too sick, too weak from previous anticoagulant rodenticide exposure used to kill rats,” Smith-Blackmore said, noting those birds provide “great rat control services” already.

The ISD has already phased anticoagulant rodenticides except for sewer baiting because “there are no approved products for sewer use,” Del Rio told councilors.