Bat Exclusion: The Only Legal Way to Remove Bats From Your Home

If you have bats in your attic, you cannot simply trap them, poison them, or seal them out at any time of year. Bats are federally and state-protected wildlife, and improper removal is illegal in every US state. Here's what you need to know about the only legal and effective method: professional bat exclusion.

All bat species in the United States are protected under state wildlife laws, and many are protected under the federal Endangered Species Act. The little brown bat and big brown bat — the two most common attic-dwelling species — have experienced dramatic population declines due to white-nose syndrome, a fungal disease that has killed millions of bats across North America.

Killing bats, using pesticides to remove them, or sealing them inside a structure (which causes them to die) is illegal and can result in significant fines.

Bat exclusion is the process of allowing bats to exit a structure through one-way devices while preventing them from re-entering. It does not harm the bats — they simply leave to forage at night and cannot return.

1. Inspection A licensed bat exclusion specialist inspects the entire structure, identifying every entry point. Bats can enter through gaps as small as ⅜ inch — the width of a pencil. Common entry points include:

• Ridge caps and roof vents
• Gaps between fascia boards and siding
• Chimney flashing gaps
• Cracks in mortar or siding
• Gaps around pipes and conduit

2. Sealing Secondary Entry Points All entry points except the primary roost entry are sealed with professional-grade materials. This step is done first to funnel bats toward the exclusion devices.

3. Installing One-Way Exclusion Devices One-way tubes or netting are installed over the primary entry points. Bats can push through to exit but cannot re-enter. Devices remain in place for a minimum of 3–7 days to ensure all bats have exited.

4. Final Sealing Once all bats have exited, the exclusion devices are removed and the primary entry points are permanently sealed.

5. Attic Cleanup Bat guano (droppings) accumulates quickly and poses serious health risks. Cleanup involves removing contaminated insulation, vacuuming guano, and treating affected surfaces with EPA-registered disinfectants.

This is where most DIY attempts fail — and where unlicensed contractors cause legal problems for homeowners.

Female bats give birth in late May or early June and raise their pups through July and into August. During this period — typically May 1 through August 15 in most northern states — bat exclusion is prohibited.

Why? Pups cannot fly until they are 3–4 weeks old. If exclusion is performed during maternity season, the mother bats are locked out while their flightless pups are trapped inside. The pups die, creating a decomposition and odor problem, and desperate mothers often find new entry points into living spaces.

Exact dates vary by state. Always confirm with a licensed professional in your area.

If you discover bats during the exclusion blackout period, a licensed professional can:

• Confirm the species and colony size
• Identify all entry points
• Seal any gaps that lead to living spaces (to prevent bats from entering your home)
• Schedule exclusion for the appropriate window

Bats are the leading source of rabies transmission to humans in the United States. You cannot always tell if a bat is rabid — infected bats do not always display obvious symptoms. If you wake up to find a bat in your bedroom, or if a bat has had contact with a sleeping person, child, or pet, contact your local health department immediately.

Bat guano can harbor Histoplasma capsulatum, a fungus that causes histoplasmosis — a respiratory illness that can be serious in immunocompromised individuals. Guano should never be disturbed without proper respiratory protection.

Similar to bed bugs, bat bugs infest bat roosts and can migrate into living spaces when bats are removed. A thorough cleanup addresses this risk.

Bat exclusion costs vary based on:

• Colony size
• Number of entry points
• Extent of guano accumulation
• Whether attic cleanup and insulation replacement are needed

A typical bat exclusion project ranges from $500 to $3,000+. Attic cleanup and insulation replacement are additional costs but are often necessary for health and energy efficiency reasons.

The cost of doing nothing is higher: a colony of 100 bats produces approximately 30 pounds of guano per year, which degrades insulation, damages wood, and creates ongoing health risks.

Bat exclusion requires:

• Knowledge of state and federal wildlife regulations
• Understanding of bat biology and seasonal restrictions
• Experience identifying all entry points (missing even one means the exclusion fails)
• Proper equipment for working at heights and in confined spaces
• Rabies pre-exposure vaccination (required for all our field technicians)

Unlicensed contractors who perform exclusion during maternity season expose homeowners to legal liability and often create worse problems than they solve.

Wildlife Removal Specialists provides professional bat exclusion throughout our 32+ service markets. All technicians are licensed, insured, and rabies-vaccinated.

Call (800) 319-1556 for a free inspection. We'll identify the species, locate all entry points, explain the timing requirements for your state, and provide a written quote.

Find your city to confirm we serve your area.