Bats in the Attic: New York's Rules and the Right Way to Get Them Out

A colony of bats in your attic is a real health and structural concern, but it's also a job with rules — New York's bats are beneficial, insect-eating animals, and several are protected. That means the way you get them out matters, both legally and ethically. Done wrong, bat 'removal' can be inhumane, illegal, and ineffective. Done right, it solves the problem for good.

Exclusion, not extermination

The correct method for bats is exclusion, not killing. That means installing one-way devices at the entry points that let bats leave to feed but not return, then sealing every gap once the roost is empty. In Central New York, little brown and big brown bats typically enter through gaps at the roofline, ridge, gable vents, and where additions meet the house — openings as small as a thumb-width.

The maternity-season restriction

This is the part homeowners often don't know: New York restricts bat exclusion during the maternity season, roughly May through mid-August, because flightless pups in the roost would be trapped and die if the adults were excluded. Reputable operators respect that window. The ideal time for exclusion is late summer into fall, after pups can fly and before bats leave for winter. A single bat that gets into living space can be removed anytime — but full colony exclusion is scheduled around the season.

Health, cleanup, and doing it once

Bats can carry rabies, and accumulated guano poses a respiratory health risk, so bat work isn't a DIY project. A proper job combines humane one-way exclusion, thorough sealing of every secondary entry point (bats exploit any gap you miss), and cleanup and decontamination where droppings have built up. The thoroughness of the sealing is what determines whether it's a permanent fix — which is exactly why it's worth hiring someone who does it correctly the first time.

Why the timing restriction exists

New York restricts bat exclusion during the summer maternity season, and the reason is concrete rather than bureaucratic. Females gather in maternity colonies to raise young, and the pups are flightless for several weeks. Sealing the adults out during that window leaves the pups inside to die — inhumane, and in practice it produces a serious odor and cleanup problem inside a wall or attic, which is a far worse situation than the one being solved.

It is also why an operator willing to seal a maternity roost mid-summer is not offering you a favor. Inspection can happen at any time; the exclusion itself has to be scheduled for the permitted window.

How exclusion is actually done

Bat exclusion is not trapping and it is not treatment. The method is to identify every access point, seal all of them except the active ones, and fit one-way devices at those so bats can leave but cannot re-enter. After enough time has passed to be confident the roost is empty, the last openings are closed.

The reason a complete inspection matters so much is that partial sealing is worse than none: closing most access points while leaving animals inside traps them. On a large or complex roofline that inspection takes real time, and it is the part of the job that determines whether the rest works.

Cleanup is a separate consideration. Accumulated guano in an attic warrants proper handling rather than casual removal.