Bat Removal

Bat Removal and Exclusion in Nassau and Suffolk County: Long Island's Bat Season and NYSDEC Regulations

April 4, 2025·11 min read

Long Island homeowners in Nassau and Suffolk County deal with bat infestations more frequently than most people realize. The dense residential housing stock — Cape Cods, colonials, and ranch-style homes built in the post-war era — provides exactly the warm, dark attic spaces that little brown bats and big brown bats need for maternity colonies. Understanding Long Island's bat season, the legal constraints that govern exclusion work, and what to expect during a professional removal will help you navigate a bat problem without running afoul of New York State regulations.

Why Long Island Has a Bat Problem

Nassau and Suffolk County offer bat colonies everything they need: warm attic spaces, proximity to water (ponds, wetlands, and the shoreline), and an abundant insect food supply. Bats are highly beneficial to the environment — a single little brown bat consumes up to 1,000 mosquitoes and other insects per hour — but when a colony establishes itself in a residential attic, the accumulating guano and potential rabies exposure risk make professional intervention necessary.

Long Island's older housing stock is particularly vulnerable. Homes built between the 1940s and 1970s in Nassau County communities like Levittown, Garden City, and Hempstead often have deteriorating wood fascia boards, gaps behind aluminum soffits installed over original wood, and aging roof-to-wall flashings that provide dozens of potential entry points. Bats can enter through openings as small as three-eighths of an inch — roughly the diameter of a dime.

In Suffolk County, the wooded character of communities like Huntington, Smithtown, and Brookhaven means bat populations remain robust, and the interface between forested lots and residential structures creates frequent bat-human contact. Properties near the Pine Barrens or Long Island Sound shoreline tend to see the highest bat activity.

New York's Bat Season: The Legal Exclusion Windows

The most important thing Nassau and Suffolk County homeowners need to understand about bat removal is that it is strictly regulated by the New York State Department of Environmental Conservation (NYSDEC). Bats are protected under both the federal Migratory Bird Treaty Act and New York State law. Killing bats — even inside your own home — is illegal, and exclusion work must be timed around the maternity season.

New York's bat maternity season runs from approximately June 1 through August 15. During this period, female bats have given birth and are nursing flightless pups. If exclusion devices are installed during the maternity season, the adult females can exit through the one-way valves, but the flightless pups cannot follow. The young bats are trapped inside, die, create severe odor problems, and represent a rabies exposure risk if they enter living spaces before dying.

Legal exclusion windows for Long Island are:

• Spring window: Mid-April through May 31. This is the earlier window, before females give birth. The risk with spring exclusion is that if any pups are born unusually early, they may be trapped inside.
• Fall window: August 16 through October. Most licensed operators prefer the fall window because all pups are flying, the colony is fully mobile, and there is adequate time before winter temperatures drive bats into hibernation.

Any contractor who offers to do bat exclusion work in Nassau or Suffolk County between June 1 and August 15 is either uninformed about state law or willing to cut corners. Neither is acceptable. Responsible wildlife control operators in New York will schedule exclusion work within legal windows only and will be upfront about this limitation.

Health Risks: Rabies and Guano Contamination

Nassau County Department of Health and Suffolk County Department of Health both maintain active rabies monitoring programs. Bats are consistently the most common rabies vector in New York State. The danger with bats is that their teeth are so small that a bite may not be felt — particularly during sleep. Any situation in which a bat was present in a room with a sleeping person, an unattended child, or anyone who cannot confirm they were not bitten should be treated as a potential rabies exposure.

If you find a bat in your home, do not release it outdoors. If possible, contain the bat using thick leather gloves and a coffee can or similar container for rabies testing. Contact Nassau County Health at (516) 227-9717 or Suffolk County Health at (631) 852-5999 for guidance on testing and post-exposure prophylaxis.

Beyond rabies, bat guano accumulating in attic spaces supports the growth of Histoplasma capsulatum, a fungus that causes histoplasmosis. Disturbing dried guano without proper respiratory protection aerosolizes fungal spores that can cause serious pulmonary disease. Guano remediation must be performed by professionals using P100 respirators, Tyvek suits, and wet-removal methods. This is not a DIY task.

The Exclusion Process for Long Island Homes

A professional bat exclusion on a Nassau or Suffolk County home follows a standardized process:

1. Exterior inspection: A licensed NWCO (Nuisance Wildlife Control Operator) inspects the full exterior at dusk, observing bat exit flights to identify active entry points. Entry points are marked and photographed. Look for dark staining — accumulated guano and body oils — around gaps at eaves, ridge caps, soffit returns, and behind shutters.
2. Interior attic assessment: Guano accumulation is assessed for volume and depth. The primary roost location is identified. Interior gaps where bats may be entering living spaces are located.
3. Secondary point sealing: All gaps that are not active primary entry points are sealed first — caulk for hairline cracks, hardware cloth for larger gaps, and foam backer rod plus caulk for irregular openings.
4. One-way exclusion device installation: Bat valves or exclusion netting is installed over active entry points during a legal exclusion window. Devices remain in place for a minimum of five to seven days.
5. Final sealing: After all bats have exited, exclusion devices are removed and primary entry points are permanently sealed.
6. Guano remediation (if needed): Contaminated insulation is removed, enzyme-based decontaminants are applied, and new insulation is installed.

Common Entry Points on Long Island's Housing Stock

Long Island's Cape Cod and ranch-style homes built in the 1950s and 1960s present recurring bat entry vulnerabilities:

• Ridge vents: Unscreened or deteriorated ridge vent caps are among the most common bat entry points in Long Island attics. Modern ridge vents have integrated insect and pest screening; older installations do not.
• Soffit returns: The gap between the original wood soffit and subsequently installed aluminum or vinyl replacement soffits frequently creates a hidden void where bats roost.
• Fascia board deterioration: Rotted wood fascia at the eave line creates gaps directly above the attic space. Bats follow the roofline and enter wherever the fascia has pulled away from the frieze board.
• Chimney-to-roof junctions: Failing step flashing and missing mortar at the chimney base create bat-accessible gaps, particularly on the north-facing side where ice and water damage is most common.
• Gable vents: Older gable vents with deteriorated screening are a classic bat entry point in Long Island homes. The screens must be replaced with heavy-gauge hardware cloth.

NYSDEC Licensing and What to Ask Your Contractor

Wildlife removal in New York requires a Nuisance Wildlife Control Operator (NWCO) license issued by the NYSDEC. For bat exclusion specifically, ask any contractor you consider hiring to confirm their NWCO license number and to explain their procedure for scheduling work within legal exclusion windows. A contractor who does not mention the June 1 to August 15 exclusion prohibition or who offers to do the work immediately regardless of the calendar date is not operating within state law.

Wildlife NY holds a current NYSDEC NWCO license and operates exclusively within legal exclusion windows. We serve all of Nassau County and Suffolk County, including the North Shore, South Shore, East End, and Five Towns communities. Call (516) 447-4673 to schedule a free inspection.

Frequently Asked Questions