Bat Removal Laws in Massachusetts: What Homeowners Need to Know
August 27, 2026
A little brown bat roosting in your attic isn’t just a nuisance in Massachusetts — it’s a legally protected animal, and handling it the wrong way can trigger fines under state wildlife law. Bat removal laws in Massachusetts are stricter than most homeowners expect, covering everything from which months you’re allowed to exclude a colony to whether you can hire just anyone to do the job.
Understanding these rules matters because Massachusetts has lost more than 90% of its cave-hibernating bat population to white-nose syndrome over the past decade and a half, pushing state wildlife officials to tighten protections rather than loosen them. This guide walks through what’s legal, what’s restricted, and what to do if you find a bat inside your house right now.
Are Bats a Protected Species in Massachusetts
Most of the bats you’ll encounter in Massachusetts carry legal protection, whether you realize it or not. The Commonwealth is home to 9 species of bats and 8 of those are listed under the Massachusetts Endangered Species Act (MESA), according to MassWildlife’s Natural Heritage & Endangered Species Program.
The little brown bat (Myotis lucifugus) illustrates why. As a result of white-nose syndrome, all four bat species that spend winters in caves or mines were listed as Endangered in Massachusetts in 2012, including the Little Brown Bat, Northern Long-eared Bat, Eastern Small-footed Bat, and Tricolored Bat. The Little Brown Bat was once the most abundant bat species in Massachusetts, but its population declined by more than 99% after the onset of the disease. The northern long-eared bat (Myotis septentrionalis) carries even heavier legal weight. NLEB is also listed as Endangered under the Massachusetts Endangered Species Act (MESA, M.G.L. c. 131 A), on top of its federal Endangered Species Act status.
Not every bat you find indoors qualifies for the strictest protections, though. Most bats found in buildings during warmer months are either big brown bats or little brown bats, and the big brown bat (Eptesicus fuscus) is not currently MESA-listed, since it wasn’t hit as hard by white-nose syndrome. Two common bats found in Massachusetts are the Little Brown Bat (Myotis lucifugus) and the Big Brown Bat (Eptesicus fuscus), per Mass Audubon, and both look nearly identical to an untrained eye — which is exactly why the law treats bat removal cautiously across the board. If you’re comparing how other states classify nuisance wildlife versus protected species, the wildlife removal laws in Virginia and the wildlife removal laws in North Carolina offer a useful side-by-side for the broader East Coast region.
Key Insight: Because most homeowners can’t tell a little brown bat from a big brown bat on sight, Massachusetts law effectively requires everyone to treat attic bats as if they’re protected — the non-lethal exclusion rules apply regardless of species.
Is It Legal to Remove Bats from Your Home in Massachusetts
You can legally remove bats from your Massachusetts home, but only through approved, non-lethal methods — killing, trapping, or possessing a bat without authorization crosses into illegal territory fast. Under Massachusetts General Laws Part I Title XIX Chapter 131 Section 90, it is unlawful to trap any bird or mammal except as authorized by MassWildlife, and that statute covers bats along with nearly every other wild mammal in the state.
State guidance puts it plainly: bats “may not be killed or captured except under permit” when they pose a public health risk or damage property. That single line is why lethal pest control tactics like poison, sticky traps, or sealing bats inside a structure are off the table entirely.
Exclusion is different from trapping in the eyes of the law, which is why it’s the go-to legal method. Massachusetts requires non-lethal approaches through the use of one-way doors, allowing bats to leave a structure on their own schedule rather than being physically captured. This distinction matters for homeowners who want to handle the job themselves without running afoul of state trapping restrictions.
If you’re weighing a DIY approach against calling in help, it’s worth checking how neighboring jurisdictions handle the same question — the wildlife removal laws in Illinois show a notably different permit structure for comparison.
Bat Exclusion Season and Restricted Dates in Massachusetts
Timing is arguably the single biggest legal trap for Massachusetts homeowners dealing with bats. State law only allows exclusion work during two specific windows each year, and getting the timing wrong can either violate wildlife protection rules or accidentally trap and kill young bats inside your walls.
Under state law, attempts to evict a bat colony can only take place during the month of May or from August 1 to mid-October, according to MassWildlife as reported by MassLive. Outside those windows, exclusion work is restricted for two very different biological reasons.
| Period | Status | Reason |
|---|---|---|
| May | Allowed | Bats have left hibernation but haven’t started raising pups yet |
| June 1 – August 15 (maternity season) | Restricted | Flightless pups are present in the roost |
| August 1 – mid-October | Allowed | Pups have fledged and can fly independently |
| Late fall through winter | Restricted | Big brown bats often hibernate inside structures |
The maternity season closure exists for a straightforward reason. Attempts to evict or exclude bats during the maternity season (June and July) may result in the death of flightless young from being trapped inside and may also lead to an increase in the number of adult bats and orphaned pups that enter the living space. Wildlife researchers cited by Catseye Pest Control note that maternity season for the commonly found little and big brown bats runs from June 1 through August 15, typically in New England. Winter carries its own risk. Bat exclusions and evictions should not be performed during the winter because big brown bats often hibernate in homes and attics, and when they awake from hibernation in the spring, they will be entrapped and may die or attempt to enter the living space to escape.
Pro Tip: If you discover bats outside the legal exclusion windows, seal off the affected room and wait for the next approved period rather than attempting a rushed removal — an improperly timed exclusion can trap pups and create a bigger problem, plus potential legal exposure.
Approved Bat Removal Methods in Massachusetts
Only one method is legally recognized for permanent bat removal in Massachusetts: exclusion using one-way doors, followed by sealing the structure. The only long-term solution to keep bats out is to bat-proof the entire house by blocking all possible entrances that are 1/2 inch or larger using a good sealing material, leaving one primary entrance fitted with a one-way device until the colony has left.
Approved methods generally include:
- Installing one-way exclusion devices over the primary entry point so bats can leave but not re-enter
- Sealing all secondary gaps, cracks, and openings larger than half an inch with caulk, mesh, or flashing
- Timing the work to fall within the May or August 1–mid-October windows
- Leaving exclusion devices in place for several days to a week to allow all bats to exit
- Installing a bat house nearby as an alternative roost once the colony has been excluded
Prohibited methods include lethal traps, poisons, fumigants, sealing an active entrance while bats are still inside, and any physical harm to the animals. Trapping or capturing bats — as opposed to letting them leave on their own — falls under separate permitting rules. Some PAC agents are equipped to handle bats specifically. PAC agents may legally handle a variety of species, including certain species of bats, and homeowners who want the work done professionally typically go this route rather than attempting to relocate a colony themselves. For comparison, states with different climates and bat species face different exclusion rules; the wildlife removal laws in Arizona reflect a very different regulatory approach shaped by desert-dwelling bat species.
Do You Need a Permit to Remove Bats in Massachusetts
Whether you need a permit depends on what kind of removal you’re doing. Straightforward exclusion — installing one-way doors and sealing gaps so bats leave voluntarily — generally doesn’t require a homeowner to hold a state permit, since it doesn’t involve trapping or capturing the animal. Homeowners who wish to hire someone to safely evict a bat colony can contact a licensed Problem Animal Control agent if they’d rather not handle the work themselves.
Anyone offering to trap bats commercially, however, needs formal state authorization. Anyone who traps any bird or mammal for hire, or who advertises or holds oneself out as a trapper for hire, must obtain a problem animal control (PAC) agent license from MassWildlife. A PAC agent license is valid for one year and requires passing an exam, paying a fee, and submitting reports, which is why vetting a contractor’s license before hiring matters as much as checking their reviews.
Important Note: A license to trap general nuisance wildlife doesn’t automatically cover bats. Because several bat species are MESA-listed, confirm that any PAC agent you hire is specifically authorized to handle bat exclusions before signing a contract.
Massachusetts isn’t unique in requiring licensed operators for sensitive species — the wildlife removal laws in Wisconsin and the wildlife removal laws in California both apply similar licensing thresholds for protected or regulated wildlife.
What to Do If You Find a Bat Inside Your Home in Massachusetts
A single bat flying through a living room calls for a different response than a colony in the attic. MassWildlife’s guidance and the associated Capturing a Bat: What You Need and How to Do It resource walk through the safe capture-and-release method: close the bat into one room, turn off the lights, open a window or exterior door, and let it find its own way out once it calms down.
If direct contact occurred, the situation changes immediately. MassWildlife’s resources include instructions for what to do if a person has had direct contact with a bat or if a bat has been discovered in a room with a sleeping person, since bats can bite without leaving an obvious mark. In those cases, do not release the bat — contact your local board of health or physician promptly, since rabies exposure protocols may call for the bat to be tested. If you’re also dealing with a pet that may have had contact with a bat, checking your dog or cat’s rabies vaccination status against pet vaccination laws in Massachusetts is a reasonable next step, since the state requires current rabies vaccination for dogs and cats.
Anyone who finds a larger colony — ten or more bats — is asked to report it. Due to recent catastrophic mortalities of bats from White Nose Syndrome, MassWildlife biologists would like reports of summer bat colony locations, so if you see a colony of bats (10 or more bats), they ask that you let them know. This isn’t a legal requirement, but it feeds directly into the state’s bat conservation tracking efforts.
If you come across a dead bat on your property rather than a live one, disposal and handling still carry health considerations similar to other wildlife carcasses; the general principles outlined in roadkill laws in Massachusetts offer relevant context on handling found wildlife remains safely.
Penalties for Illegal Bat Removal in Massachusetts
Massachusetts backs its bat protections with real enforcement, not just guidance documents. Massachusetts enforces its wildlife laws through the Environmental Police and MassWildlife, and violations can result in fines, criminal charges, equipment forfeiture, and mandatory restitution, with penalties that scale with the severity of the offense.
Under M.G.L. Chapter 131, Section 90, a violation of the chapter for which no other penalty is specified carries a fine of not less than $200 per offense, and repeated or more serious violations — such as killing a MESA-listed species like the northern long-eared bat — can escalate well beyond that baseline. Because the northern long-eared bat also carries federal Endangered Species Act status, harming one can potentially trigger separate federal enforcement on top of state penalties, layering additional legal risk onto what might seem like a simple pest control decision.
For a broader look at how Massachusetts structures penalties across wildlife categories beyond bats, the full breakdown in wildlife removal laws in Massachusetts covers the PAC licensing framework and species-by-species enforcement in more detail. Homeowners weighing DIY removal against professional help should also compare how enforcement looks elsewhere — the wildlife removal laws in Minnesota apply a noticeably different penalty structure for similar violations.
Pro Tip: Before attempting any bat removal yourself, a quick call to MassWildlife’s district office or a licensed PAC agent costs nothing and can confirm whether your timing, method, and target species keep you on the right side of state law.
Bat removal in Massachusetts sits at the intersection of pest control and wildlife conservation, and the rules reflect that tension. Stick to the May and August–October exclusion windows, use one-way doors and sealing rather than lethal methods, and lean on a licensed PAC agent when a colony is involved rather than a single stray bat. Getting the timing and method right protects both your home and a bat population that’s already been hit hard by disease.