How To Get Rid Of Bats Outside Your Home: Safe, Legal Deterrent & Exclusion Guide

Safely and humanely mitigating bat activity on your home's exterior requires a dual strategy of sensory disruption and physical exclusion, strictly timed to avoid restricted maternity windows. By utilizing high-lumen directional lighting, installing 1/4-inch galvanized hardware cloth, and deploying properly configured one-way exit valves, homeowners can permanently deter roosting colonies without violating federal conservation laws. Executed correctly, this systematic approach protects your structural integrity while respecting local ecosystems.

Pre-Operation Analysis and Tactical Equipment Checklist

Before initiating any bat mitigation protocol, you must understand the legal and biological framework governing these mammals. In many jurisdictions, bats are heavily protected under the Endangered Species Act and state-level wildlife conservation laws. It is a federal offense to harm, kill, or trap bats, or to perform exclusion tactics during the maternity season—typically running from mid-May through mid-August in North America—when non-flying pups can be trapped inside and perish.

To execute a safe, legal, and highly effective exterior bat remediation program, prepare your materials, assess structural vulnerability, and establish your budget beforehand.

Required Materials, Gear, and Project Benchmarks

• High-Intensity Directional Lighting: Minimum 2,000 lumens LED floodlights with weatherproof IP65 casings.
• Physical Barrier Material: 1/4-inch galvanized steel hardware cloth or heavy-duty copper mesh. Avoid plastic netting, which can tear or trap bats by their claws.
• Exclusion Devices: Professional-grade commercial exclusion cones or DIY 2-inch diameter PVC pipes (approximately 10 inches in length), or clear poly-sheeting (4-mil thickness).
• Structural Sealants: Premium exterior-grade polyurethane caulk, expandable foam with pest-blocking agents, and heavy-duty staple guns with galvanized staples.
• Visual and Acoustic Deterrents: Holographic Mylar scare tape (2 inches wide) and high-frequency ultrasonic deterrent systems designed specifically for exterior structural mounting.
• Personal Protective Equipment (PPE): N95 or HEPA-filter respirator mask (to protect against Histoplasma capsulatum fungal spores found in guano), heavy-gauge leather work gloves, and impact-resistant safety goggles.
• Projected Budget: $150 to $600 depending on structural height, ladder requirements, and the linear footage of the eaves.
• Projected Timeline: 7 to 14 days, including active observation, device installation, and final structural sealing.

Step-by-Step Exterior Bat Deterrent and Exclusion Protocol

Step 1: Conduct a Nighttime Emergence Survey and Site Inspection

To solve an exterior bat issue, you must locate their precise roosting zones and flight paths. Bats commonly roost under roof eaves, behind window shutters, in fascia board gaps, or inside the soffits of porches.

1. Begin your inspection 30 minutes before local sunset and continue observing for 45 minutes after sunset.
2. Position observers at opposite corners of the home to get a complete 360-degree view of the roofline and gables.
3. Note where bats emerge. Look for structural gaps as small as 3/8 of an inch (9 mm)—approximately the size of a human pinky finger or a dime.
4. Inspect the ground and exterior walls during daylight hours for guano deposits. Bat guano resembles mouse droppings but features a shiny, brittle texture that easily crushes into tiny, metallic insect-wing fragments when dry. You may also observe dark, oily rub marks on the siding or fascia caused by the natural oils in the bats' fur as they squeeze into tight crevices.

Warning: Never handle bat guano with bare hands or dry-sweep it. Inhaling airborne dust from dry guano can transmit histoplasmosis, a severe respiratory disease. Always saturate the area with a 10% bleach-water solution and wear an N95 respirator before remediation.

Step 2: Time Your Intervention Around Regional Maternity Windows

Exclusion and active physical deterrent installation must only occur when you are certain no flightless bat pups are present on the exterior structure.

1. Contact your local state extension office or Department of Natural Resources (DNR) to verify the exact maternity season dates for your region.
2. If your survey reveals bat activity during active maternity months (typically May 15 to August 15), do not install exclusion cones or seal any entry points. Doing so traps the juvenile pups inside or on the exterior walls, leading to starvation, decay, odor issues, and desperate bats chewing into the interior living spaces of your home.
3. During restricted months, limit your efforts to non-trapping sensory deterrents, such as exterior lighting and reflective devices, which encourage parent bats to relocate their roosts naturally without physical confinement.

Step 3: Implement High-Lumen Sensory Disruption

Bats are nocturnal mammals that seek dark, quiet, draft-free spaces to rest during daylight hours. Introducing targeted light and motion to their preferred roosting zones makes the environment highly undesirable.

1. Mount weatherproof, 2,000-lumen (minimum) LED floodlights directly beneath the eaves, soffits, or porch overhangs where bats are roosting.
2. Direct the beams upward into the crevices and corners where the bats hang. Continuous white light (5,000K to 6,500K daylight spectrum) disrupts their circadian rhythm and prevents them from sleeping.
3. Hang 18-to-24-inch strips of holographic Mylar tape directly in the path of the light and wind currents near the roosting site. The metallic, shimmering reflections combine with the crinkling sound of the wind to disrupt the bats' sensitive echolocation and visual senses.
4. Leave these sensory deterrents operational 24 hours a day for at least 7 consecutive days to break their nesting habits.

Step 4: Install Professional-Grade One-Way Exclusion Devices

For bats roosting within deep structural voids (like behind gables, siding, or trim boards), you must allow them to exit safely at night while blocking their return path.

1. Construct or purchase a rigid exclusion cone or a flexible plastic sleeve. If building your own, cut a 10-inch length of 2-inch diameter PVC pipe or clean plastic sheeting.
2. Secure the top and sides of the exclusion device directly over the active exit gap using polyurethane caulk and staples. Ensure there are zero gaps around the perimeter of the mounting flange.
3. Angle the exclusion tube downward at a 45-degree angle. If using flexible plastic sheeting, create a drape that hangs 18 to 24 inches below the exit point, securing the top and sides while leaving the bottom completely open.
4. As bats exit at dusk, they crawl down through the tube or slide under the plastic drape and fly away. When they return, their natural instincts direct them to land directly on the entry gap; they cannot hover and crawl back up through the narrow, slippery tube or navigate under the loose hanging drape.

Pro-Tip: Ensure all non-active gaps within 15 feet of the exclusion device are sealed with polyurethane caulk or steel mesh before opening the exclusion channel. Otherwise, bats will immediately colonize the adjacent structural cracks upon being locked out of their primary entry point.

Step 5: Seal the Exterior and Apply Physical Barriers

After leaving the exclusion devices in place for 5 to 7 days of clear, warm weather (when night temperatures remain above 50°F/10°C, ensuring the bats are active and feeding), you can safely seal the structure.

1. Confirm that all bat activity has ceased by conducting a follow-up emergence survey at dusk.
2. Remove the exclusion devices carefully.
3. Pack deep structural cracks with copper stuffing mesh or stainless steel wool to provide a solid backing.
4. Apply a thick, continuous bead of premium exterior-grade polyurethane sealant over the mesh. Smooth the caulk with a putty knife to ensure a completely airtight, watertight seal.
5. Cover attic vents, exhaust ports, and chimney openings with 1/4-inch galvanized steel hardware cloth. Secure the mesh edges with washers and self-tapping screws every 6 inches to prevent wind, weather, or persistent pests from prying the edges open.

Comparative Technical Specifications for Bat Deterrents

Real-World Exterior Deterrent Failures & Corrections

Bat Roosting Persists Directly Adjacent to Newly Installed Floodlights

• Root Cause: The light fixture was positioned too far away or set at an angle that cast deep shadows inside the architectural crevice, providing the bats with a shaded, protected pocket directly next to the illuminated zone.
• Actionable Fix: Adjust the mounting bracket or add a secondary low-profile LED light strip directly inside the crevice. Ensure the light beams leave zero shadow zones or dark alcoves within a 6-foot radius of the targeted area.

One-Way Exclusion Nets Trap Bats or Allow Re-Entry

• Root Cause: The exclusion netting was either too stiff, allowing bats to crawl back up under the bottom edge, or it was pinned too tightly to the wall, preventing the bats from sliding out and leaving them trapped and dying inside the wall cavity.
• Actionable Fix: Replace stiff netting with lightweight, flexible 4-mil polyethylene sheeting. Ensure the bottom edge hangs completely free, extending a full 18 to 24 inches below the lowest exit point, and rests flush against the wall surface without any folds, wrinkles, or structural protrusions that create entry pockets.

Bats Migrate to a Different Area of the Same Exterior Wall

• Root Cause: The homeowner successfully sealed or deterred bats from the primary roost but failed to identify and secure identical structural gaps nearby. Bats are highly site-loyal and will simply shift 5 to 10 feet along the same fascia line to find a new entrance.
• Actionable Fix: Conduct a comprehensive sealing sweep of the entire roofline, gable system, and eave structure. Any gap wider than 1/4 inch across the entire building envelope must be sealed with polyurethane caulk or backed by galvanized hardware cloth, regardless of whether current bat activity is present.

Frequently Asked Questions

How do I get rid of bats under my roof eaves or porch?

To eliminate bats under roof eaves or porch ceilings, combine sensory disruption with physical modifications. Install directional, weatherproof LED lights of at least 2,000 lumens focused upward into the roosting area, and hang double-sided holographic Mylar tape nearby to disrupt their flight patterns. If they continue to cling to the rough surface of your soffit or siding, install a smooth physical barrier, such as clear plexiglass sheeting or heavy-gauge vinyl, over the area to prevent their claws from gripping the surface.

What smells or natural repellents do bats hate most?

While products like peppermint oil, mothballs (naphthalene), or predator urine are frequently mentioned as home remedies, they are highly ineffective when used outdoors. Air currents quickly dilute the scent molecules, rendering them useless, and naphthalene is a known carcinogen that can contaminate your home's air intake. Reliable outdoor bat mitigation depends on physical exclusion, structural sealing, and high-intensity lighting rather than chemical or olfactory repellents.

Is it legal to spray bats with water or pest spray to force them away?

No, it is highly illegal in almost all jurisdictions to spray bats with water, pesticides, or any chemical agents. Bats are protected under federal, state, and local conservation laws, and spraying them can lead to severe fines, animal cruelty charges, or direct chemical exposure to protected species. Furthermore, spraying bats does not address the underlying structural gaps, meaning new bats will immediately re-colonize the area once the moisture or chemicals dissipate.

When is the best time of year to get rid of bats outside?

The ideal windows for physical bat exclusion and permanent sealing are early spring (before the maternity season starts in May) or late summer and early autumn (after the pups have learned to fly, typically starting in mid-to-late August). During these periods, night temperatures are warm enough for the bats to leave their roosts nightly to forage, allowing you to safely install exclusion devices and seal structural gaps without risking the entrapment of flightless young.

Secure Your Home with Professional-Grade Pest Defense

If your efforts to humanely exclude bats reveal complex structural issues or high-altitude entry points, do not compromise your safety. Contact a licensed wildlife management professional to perform a comprehensive, legally compliant exclusion and safeguard your property today.