rodent poison box outside local store in November 2023Rodent poison box outside a local store in November 2023 / Catherine Brewster photoUPDATED Feb. 11: Residents concerned about the potentially lethal danger to wild birds that prey on poisoned rats had a chance recently to make their views known to the U.S. Environmental Protection Agency. Three other pieces of legislation on generally the same topic are pending at the Massachusetts State House.

Individuals remain restricted from using the most potent poisons, while businesses in Arlington vary in how they cope with rodents -- and town officials, partly based on public input, continue researching ways that are safer for humans, wildlife and the environment.

A free 90-minute online opportunity to learn more about preferred approachesnow is available from the federal Environmental Protection Agency: "Managing Rodents with Integrated Pest Management aned New Technologies." It's to be at 2 p.m. Feb. 20.

"Urban environments present unique pest challenges, especially with rats and mice. New and improved approaches, including the use of artificial intelligence (AI) tools, are helping address these challenges. During this free webinar, renowned experts will share information on rodent behaviors that participants can use to refine their pest management programs. Lessons learned about specific control practices will also be discussed. The importance of integrating tactics, such as sanitation, habitat modification, exclusion and rodenticides, will be highlighted. New AI tools, such as smart cameras and sensors, to aid pest management professionals will be described in detail." People may sign up at

The issue became widely known close to a year ago, when a bald eagle named MK became a celebrated figure in Arlington and beyond. Showing signs that she had ingested second-generation anticoagulant rodenticides (SGARs), she was taken to the New England Wildlife Centers’ hospital on Cape Cod, where she died Feb. 28.

A necropsy confirmed SGAR poisoning as the cause of death. On March 2, a vigil for MK that began in front of the Cyrus Dallin Museum grew to 300 people, including local state representatives Dave Rogers and Sean Garballey, in front of Town Hall.

SGARs, with few exceptions, have been banned on town property for more than a year and are off-limits to individuals but still may be used on private property by pest-control companies.

Since then, while no poisoned birds of prey have attained the stature that MK did, several red-tailed hawks, two screech owls and a barred owl have succumbed to suspected or confirmed poisoning by SGARs in Arlington alone, according to Save Arlington Wildlife founder Laura Kiesel, who crowdfunded several necropsies to confirm the causes of death.

In response to the public uproar, the town held a rat forum in May. Since then, measures to regulate SGARs have continued their gradual advance through the state legislative process.

Rodenticides and alternatives

Retailers in Capitol Square business district exemplify a mix of practices to combat rats. On the north side of Mass. Ave., owners of Arlington Bakery and Clay Dreams signed Save Arlington Wildlife’s Poison Free Pledge. Arlington Bakery owner and pastry chef Lika Valentzas said that since she took over in 2019, “I’ve never seen a rat.” Clay Dreams owner Lorraine Frigoletto said that she had seen a mouse or two in the store’s basement but none in the last couple of years.

Valentzas added that several other nearby businesses on the north side of Mass. Ave., including Town Tavern, share a contract with a pest-control company that uses traps but not poison. When the town Department of Public Works took down a dead tree that had a rats’ nest in it late last year, the company, A+ Pest Control of Framingham, increased its visits to twice a month until all were reassured.Nearby proprietors also watch each other’s trash barrels, she said, and recently ordered rugged new ones.

“It will take a community-wide effort for [nonpoisonous sterilizing bait] to be effective.” — Local homeowner Katrina Bernstein

On the south side of the street, Otto Pizza, the Capitol Theatre and Quebrada Bakery share a pest-control company (Bain Pest Control, now Ehrlich, a division of Rentokil); employees referred YourArlington to the building manager, who has not responded to requests for comment, but a bait box in the alley seen late last year suggests that rodenticides are in the mix. On the same block, the YES! (Your Eco Source) store has signed the Poison Free Pledge and doesn’t use a pest-control company at all. The business is environmentally oriented, but “People don’t tend to come into the store asking for ways to kill rats,” said owner Ceilidh Yurenka, because the store focuses on reducing plastic waste.

In the Kelwyn Manor neighborhood, bounded by Spy Pond, Lake Street and Route 2, one homeowner, Katrina Bernstein, has been looking into Contrapest — bait that acts as birth control on rodents. “I’m hoping that I can get several neighbors to also commit to using it,” she said, “because it will take a community-wide effort for it to be effective. Plus we can go in together on purchasing the larger refills once we all have the bait stations.” Residents who are short on time but hope to avoid using poisons may view the list of resources at the end of this article for more on such alternatives.

The townwide scene: bait boxes visible

SGARs have been prohibited on town property since Jan. 4, 2023, but under state law (see more below) the town cannot regulate rodenticides on private property. In recent months, this reporter saw few large apartment buildings and businesses on Massachusetts Avenue between Capitol Square and Arlington Center without bait boxes tucked somewhere along an exterior wall. As of two months ago, at least four such boxes were visible outside Whole Foods in Arlington Center, the scene of protests last winter. Two different Whole Foods managers asked about the store’s use of rodenticides would not comment, referring YourArlington to corporate media relations, which did not respond.

“Rats can outbreed any poison, but their predators can’t.”  — Save Arlington Wildlife founder Laura Kiesel

It seems likely that in the absence of active resistance to poison, it’s routinely deployed. SGARs can be applied only by licensed pesticide applicators — the companies that residents and businesses are likely to call for help and who may or may not elaborate on the risks — in tamper-resistant bait boxes. However, rats who ingest them don’t die immediately, instead becoming easy targets for predators — and passing accumulating doses up the food chain.

As Kiesel put it, “Rats can outbreed any poison, but their predators can’t …Tufts Wildlife Clinic, a national authority on SGARs poisonings in birds of prey, has recorded trends of increased SGARs in owls, hawks and eagles in Massachusetts (specifically, their research found that 100 percent of red-tailed hawks surveyed were impacted and that 96 percent of all birds of prey surveyed overall).” The study is here>>

Confirmed poisonings like the case of MK, as well as the great horned owl family in Menotomy Rocks Park in 2022 and a Cooper’s hawk fledgling in the same year, probably represent a very small percentage of the toll on predators, according to Kiesel. “Many other animals are not necropsied but simply disposed of because of costs; necropsies are expensive, and many wildlife rehabbers run on shoestring budgets.”

Arlington’s evolving strategies

Arlington’s director of public health, Natasha Waden, emphasizes that “the Health Department has always approached these situations with a focus on Integrated Pest Management (IPM) strategies,” whether on public or private properties. She said that IPM emphasizes “an environmentally friendly approach prior to the use of other treatment methods. When treatment methods need to be considered, IPM looks at methods that minimize the risk to human health, non-target organisms and the environment.”

“ ‘Best Practices for Pest Proofing Food Establishments’ continue to be discussed with owners/managers during our routine food inspections.” Town director of Public Health Natasha Waden

These methods begin with avoiding practices that tend to attract rodents in the first place; see below for details.

Waden considers the May forum to have been a success, generating more than 150 comments from participants. “Education and communication were identified as the largest category. We continue to refer back to these comments/suggestions.” Steps the town has taken since May include “increased social media presence during times of high rodent activity to encourage IPM practices” and “new educational brochures, such as ‘Best Practices for Pest Proofing Food Establishments,’ which continue to be discussed with owners/managers during our routine food inspections.”

A yearlong pilot program deploying six SMART boxes -- electronic traps that record data when they make a catch -- produced mixed results. Waden has concluded that “they are really meant to be deployed in a location where there might be high rodent activity and the food/water sources are less controllable.” Standard IPM practices seemed to work as well or better otherwise. For instance, near a dumpster with a rusted-out bottom, “while we did get some catches, high rodent activity persisted. Once the dumpster was replaced and the active burrows were treated (fumigation with carbon dioxide), the problem went away. In speaking with some of our neighboring communities, we heard similar stories.”

She added that as part of the MetroHealth Regional Collaborative, Arlington is working with Belmont, Brookline and Newton “to share information about best practices and explore the possibility of a regional educational campaign.” Next steps for Waden include “additional outreach/educational materials to be distributed to our large residential-property owners/managers.”

State-level action underway 

Three bills with a bearing on SGARs in Arlington were the subject of a May 10 hearing by the state’s Joint Committee on Environment and Natural Resources (CENR). Kiesel, after a rally outside the State House, was the first of many who testified in support of the bills and invoked MK’s memory.

Two of the bills would allow municipalities to regulate SGARs more strictly than the Massachusetts Department of Agricultural Resources (MDAR), which has jurisdiction over pesticides. H.804 would grant Arlington’s petition for home rule in phasing out SGARs, as approved nearly unanimously by Town Meeting in 2022.

[Make] the state regulations “the floor instead of the ceiling.” legislation sponsor state Rep. Carmen Gentile (13th Middlesex)

 H.814 would allow any Massachusetts municipality to regulate pesticides more stringently than MDAR does, making the state regulations “the floor instead of the ceiling,” as the bill’s sponsor, Rep. Carmen Gentile (13th Middlesex), said at the hearing.

The third bill, H.825, would establish statewide monitoring of where SGARs are placed and their effectiveness. Known as the Hawkins bill after its sponsor, Rep. James Hawkins of Attleboro, it was voted favorably out of the CENR in September and is now before the Ways and Means Committee. Like H.814, it has a longer list of petitioners than H.804. H.825 has other backers that include some Republicans as well as the MSPCA and national organizations like Raptors Are the Solution. These supporters can be seen here>>

Rogers and Garballey are petitioners on all three bills, and local state Sen. Cindy Friedman presented H.804 with Garballey. As a panel, the three testified at the May 10 hearing.

Town’s home-rule petition’s progress

Rogers told YourArlington in January that, while the CENR had until Feb. 7 to make its decisions on H.804 and 814, “it is difficult, if not impossible, to predict when their next moves will happen. On H.804, Arlington’s home-rule petition, I am hopeful the bill will move.”

The CENR’s May hearing also included testimony on no fewer than three bills with the title “An Act relative to the pesticide board,” a subcommittee within the Department of Agricultural Resources. One, H.873, would create a “pesticide control modernization and environmental protection task force,” to be chaired by the secretary of energy and environmental affairs and include the commissioners of environmental protection and public health. One presenter, Rep. Mindy Domb of Amherst, testified at the May hearing that too many conflicts arise under the current regulatory structure. Cecily Miller of Cambridge, urging support for Arlington’s home-rule petition as well as the other two bills, said, “I’ve testified year after year and seen no changes.”

“I am a strong proponent of public advocacy and know not to underestimate it.”     — local state Rep. Dave Rogers

Opponents of H.804, 814 and 825 include the New England Pest Management Association, the trade organization for the pesticide industry as well as Nicolas John of the Massachusetts Farm Bureau Federation. John argued at the same hearing that MDAR and the EPA are better equipped than local jurisdictions to regulate pesticides and that allowing all 351 Massachusetts municipalities to create their own rules would make for “an uneven patchwork.”

Kiesel told YourArlington that Save Arlington Wildlife “has exerted some pressure on MDAR, but really, we're not going to compete with the pest control lobby. What would impress MDAR and the State House is if more municipalities joined Arlington and started pressuring them to ban SGARs.”

"On the legislative rather than the executive side, Rogers says, “I am a strong proponent of public advocacy and know not to underestimate it. I remain steadfastly committed to helping pass these important bills.” 

Federal regulation: Input accepted last month; final version due out in November

The federal EPA issued rules in 2008 that prohibit the direct sale of SGARs to consumers and require tamper-resistant bait boxes. In November 2022, the EPA issued a “Proposed Interim Decision,” which considers a requirement for “users to collect carcasses of rodents that may have consumed rodenticides to prevent further exposures to non-target organisms that could consume the carcasses.” At the end of November 2023, EPA released a draft biological evaluation, or BE, analyzing the effects of 11 rodenticides, including four SGARs, on endangered and threatened species and their “designated critical habitats.”

The draft BE notes that “in general, SGARs (i.e, brodifacoum, bromadiolone, difenacoum and difethialone) pose a greater potential risk compared to FGARs [first-generation anticoagulant rodenticides] (i.e., warfarin, chlorophacinone and diphacinone) because they only require one feeding to kill the target pest, whereas FGARs require multiple feedings. ...Open literature studies on rodenticide incidents suggest that anticoagulant rodenticides have a significant likelihood to impact nontarget wildlife; exposure rates to wild animals in these studies was high, even in remote densely forested regions with no legal uses of SGARs.

“Nevertheless, the EPA found 'jeopardy' from rodenticides only to seven endangered or threatened bird species, all of them birds or prey or scavengers, and 21 mammal species. Summarizing the more than 22,000 comments made on the Proposed Interim Decisions for rodenticides from Nov. 29, 2022, through Feb. 13, 2023, the draft BE notes, “A number of commenters were proponents for strict regulation of rodenticides due to concerns over non-target wildlife exposure, incidents and concern that not enough is being done to protect listed species.”

Several commenters cited the potential for rodenticide misuse. A significant number of comments cited the numerous benefits of rodenticide use, expressing concern that the proposed measures will substantially increase costs of rodent control, access to affordable rodenticides and users’ ability to control infestations. The proposed mitigation measure of non-refillable bait stations for consumer products raised concerns regarding the prohibition of refillable bait stations for consumer use, and the impact of single-use plastics. Concerns were raised over feasibility and effectiveness of carcass search measures. Concerns related to proposing the restricted use designation focused on a current lack of certified applicators in the professional pest applicator and livestock sectors, and the cost of certification, record-keeping and labor.

The draft BE was open for public comment until Wednesday, Jan. 24, 2024 here >> at docket ID EPA-HQ-OPP-2023-0567. Interested readers can also look here >>

After that, next steps are a final BE to be issued in November 2024, followed by consultation with U.S. Fish and Wildlife Services, which makes the final determination on jeopardy to federally listed threatened or endangered species. The communications director for the Massachusetts Department of Agricultural Resources, which would have to respond to such measures, would tell YourArlington only that MDAR awaits EPA’s final decision.

Common-sense deterents available

From Save Arlington Wildlife to pest-control companies,most sources agree that controlling rodents begins with not attracting them: removing food sources (including outdoor trash, except on the morning of pickup, and bird feeders) and blocking entry points. One cheap barrier method is steel wool.

Old-fashioned snap traps or catch-and-release traps, including bucket traps, are easy to find online and at hardware stores, but, says Save Arlington Wildlife’s Laura Kiesel, “If there isn't proper exclusion, trapping, whether lethal or nonlethal, will just be a stop-gap measure.” 

Save Arlington Wildlife's website has a page with alternatives to rodenticides.

The town’s website on rodent control has been revised and expanded after the forum held in May.

Save Arlington Wildlife's website has a special page that lists alternatives to rodenticides.

For residents who think they may have found a poisoned bird of prey, MassWildlife has a guide here >>

Tufts Wildlife Clinic has a resource page here >>

Kiesel recommends immediately calling MassWildlife “at 508-389-6300 concerning a possibly poisoned raptor. Andrew Vitz is the state ornithologist; his number is 508-389-6394.”

They also can try the Environmental Police at (800) 632-8075 or Tufts Wildlife Clinic, listed above.

“I have asked people to cc me or keep SAW in the loop on these reportings and correspondences,” she said. 

May 27, 2023: Rat czar? SGAR? People ponder perennial problem of rodent control in Arlington

This article and photograph by YourArlington freelance writer Catherine Brewster was published Monday, Jan. 22, 2024. It was updated Feb. 11, 2024, for time references and also with information about a free 90-minute online webinar about modern means of pest control to be offered by the USEPA at 2 p.m. Feb. 20.