Data the city was supposedly collecting on rat populations has mysteriously failed to appear on schedule, with city hall declining to explain where the numbers are or what may have caused their delay.

The mayor’s press office confirmed December 11 that it did not have the expected results of an extensive direct monitoring program that’s supposed to have finished initial measurements months ago. It didn’t provide any direct reasons why in its statements, saying only that officials are still gathering information.

“The city is currently collecting sensor data assessing how the various deployed interventions and technologies are affecting rodent populations,” it said in a statement.

The data would have been the first citywide effort to directly track rat populations, providing a clearer picture than measuring 311 calls or relying on complaints made to private exterminators. Begun in July 2024 with an action paper drafted with urban rodentologist Dr. Bobby Corrigan, sensors installed throughout the city to track how many rats passed them were supposed to have results ready by September or October according to officials in July.

The mayor’s office does still say that results will eventually emerge, just delayed to some ambiguous date in the months to come.

“The city is currently in the data collection phase and expects to evaluate the results in the coming months,” it said. “Once the findings are available, you can access them on boston.gov.”

The city declined to answer any follow-up questions, or to make available for interview the original officials heading the rat control effort, Special Project Manager Luke Hines and environmental services’ Assistant Commissioner John Ulrich. It did not clarify whether data from the last few months exists, or whether some obstacle stopped the collection entirely.

The city has also been rolling out experimental trash containers in specific parts of the city, hoping to test which are most effective at stifling rodent populations. Broader rollouts were to be decided based on data from the sensors, but with that data delayed it’s no longer clear what path forward those programs will take District 8 City Councilor Ed Flynn told The Boston Guardian that he hopes city officials will take the issue seriously, noting his efforts to establish a dedicated office to address pest complaints.

“The city administration included many of my recommendations as part of their overall strategy on rodent mitigation, although a major recommendation was not included, for a dedicated ‘Rat Czar’ to more effectively coordinate resources to address this major public safety and health crisis,” he said. “I now hope that my colleagues will objectively look at worsening conditions this year and support my efforts to establish an Office of Pest Control in Boston.”

Flynn also praised the new containers the city is experimenting with, though he wanted other outreach programs to roll out alongside them.

“While public trash containers in commercial areas are helpful, we need to launch a massive public awareness and outreach campaign on proper trash removal and containerization for individual residents and businesses,” he said. “It is critical to supply bait boxes, compost containers to separate the food source, and provide strict enforcement for violations. Language access is key for all communities to also understand their role in addressing a crisis that has left rodents carrying leptospirosis in Boston.”