Bat Exclusion Services

Bat exclusion is not the same thing as wildlife exclusion. Standard wildlife exclusion means sealing openings on a building to keep animals out. Bat exclusion is a phased process built around one-way devices that let bats leave on their own before the building is sealed. You cannot trap bats. You cannot seal them inside. You cannot use chemicals. The only legal method for removing bats from a structure in North Carolina is exclusion using one-way devices, and the process is governed by a state-mandated seasonal moratorium. Triangle Wildlife Removal & Pest Control is NWCOA Bat Standards Certified and has been performing bat exclusions since 1990.

Why Bat Exclusion Is Different

One-Way Exclusion Devices

A one-way device is a mechanism installed over an active bat entry point that allows bats to exit the structure through their normal flight path but prevents them from reentering. The bat leaves at dusk to forage, passes through the device, and cannot find its way back in.

The specific device type depends on the entry point:

• Exclusion tubes – rigid tubes installed over small, defined entry holes. The bat crawls through the tube to exit. The tube extends far enough from the wall that the bat drops into flight rather than circling back to the opening.
• Exclusion netting – fine mesh netting draped over larger areas (long gaps along drip edge or soffit lines) where multiple bats are entering across a broad section. The netting hangs loosely at the bottom, allowing bats to crawl out and drop away, but lays flat against the wall when approached from outside, blocking reentry.
• Exclusion cones – funnel-shaped devices used on round or irregular openings. The bat exits through the wide end of the funnel but cannot navigate back through the narrow end from outside.

Devices are installed at every active entry point simultaneously. Before the devices go up, every other gap on the structure – every crack, construction gap, deteriorated vent screen, and potential access point that bats could shift to – is sealed. The one-way devices are the only remaining openings. This forces the colony to leave through the devices rather than finding an alternate way in.

The Process Step by Step

1. Full exterior inspection. The technician examines the entire building envelope from the foundation to the ridge. Every active entry point is identified by staining (dark rub marks from bat body oils), guano deposits below the opening, and direct observation at dusk. Every potential access gap is also flagged – bats will find gaps that were not previously in use once their primary entry is blocked.
2. Interior inspection. The attic is assessed for colony size, guano accumulation, and contamination extent. This determines the scope of cleanup and restoration work that will follow.
3. Seal all secondary openings. Every gap on the structure except the active bat entries is permanently sealed using caulk, metal flashing, hardware cloth, foam backer rod, or Ridge Guard, depending on the location.
4. Install one-way devices at active entries. Tubes, netting, or cones are installed at every confirmed bat entry point. The devices are secured to prevent wind displacement and positioned to align with the bats’ flight path.
5. Monitoring period. The devices remain in place while the colony departs. The technician monitors for activity to confirm the colony is vacating. On a large colony, this may take several days to a couple of weeks.
6. Remove devices, seal final openings. Once the colony has departed, the one-way devices are removed and those final openings are permanently sealed with the same materials used on the rest of the structure.
7. Guano cleanup and attic restoration (when needed). Contaminated insulation is removed, surfaces are sanitized, ectoparasites are treated, new insulation is installed, and odors are neutralized.

Seasonal Restrictions

During the moratorium, Triangle Wildlife Removal can still perform the inspection, develop the exclusion plan, and prepare the scope of work so the project is ready to start on August 1. If bats are entering the living space during the moratorium, that is handled as a separate health and safety matter regardless of the calendar.

Common Bat Entry Points

Bats exploit gaps that most homeowners – and many contractors – would never notice. A 3/8-inch gap is enough for a big brown bat. Smaller species fit through even less.

• Ridge vent – construction gaps where the ridge cap meets the roof sheathing. This is one of the most common bat entry points on homes and is the reason Ridge Guard exists as a product.
• Drip edge – the metal flashing along the lower roof edge separates from the fascia as materials expand, contract, and settle. The resulting gap runs the full length of the roofline.
• Soffit-to-fascia junction – where the soffit panel meets the fascia board. Settling, shrinkage, and rot open gaps at this intersection.
• Gable vents – screening behind the louvers degrades. Bats pass through holes in the screen that are too small for most other animals.
• Chimney flashing – where the chimney meets the roof deck, flashing details create seams and gaps that bats access from above.
• Utility penetrations – gaps around HVAC lines, plumbing vents, and electrical conduits passing through exterior walls.
• Builder gaps under shingles – gaps at the roofline where shingles overhang the fascia. These are concealed from view and only visible during a close roof-level inspection.

Why the Whole Structure Matters

Bat exclusion cannot be done partially. Sealing the primary entry while leaving other gaps open does not solve the problem – it moves it. Bats returning to a sealed entry will search for an alternate way in, and they will find gaps that were not previously in use. A bat exclusion that addresses only the known active entries without sealing the rest of the building is incomplete, and the colony will reestablish itself through a different opening.

This is why Triangle Wildlife Removal’s bat exclusion is a full-structure approach. Every gap on the building is addressed, not just the ones where bat activity is currently observed. The limited lifetime warranty reflects this scope – when the entire structure is excluded, the warranty covers the entire building.

What Not to Do

• Do not seal a bat entry point without installing a one-way device first. Sealing bats inside the structure forces them into the living space through gaps around light fixtures, ductwork, plumbing chases, and other interior pathways. A bat flying through a bedroom is a rabies exposure concern.
• Do not attempt exclusion during the May 1 – July 31 moratorium. Flightless pups trapped inside will die in the attic or migrate into the living space. Post-exposure rabies treatment can cost thousands of dollars per person.
• Do not use chemical repellents, mothballs, ultrasonic devices, or bright lights. None of these methods are effective for bat removal. Mothballs (naphthalene) are a registered pesticide and using them in an attic for bat deterrence is an off-label use that violates federal pesticide law.
• Do not handle bats with bare hands. Bats are a rabies vector species. Any direct contact should be treated as a potential exposure.