Bat Removal and Exclusion in Indiana: What Homeowners Need to Know

January 31, 2026

Bats are among the most common nuisance wildlife calls in Indiana. A single colony of little brown bats can number 50 to 500 animals, and they return to the same roost year after year. If you hear scratching or squeaking in your attic at dusk between April and October, there is a good chance you have a maternity colony.

Why Bats Choose Your Home

Bats seek warm, dark, protected spaces for their summer maternity colonies. Common entry points include:

• Gaps under ridge cap shingles — as small as 3/8 inch
• Fascia board gaps where wood has warped or shrunk
• Attic vents with damaged or missing screens
• Chimney gaps where mortar has deteriorated
• Dormers and roof valleys where two roof planes meet

A single colony may use several different entry points across the exterior of your home.

Indiana’s Maternity Colony Season

Indiana law and DNR policy prohibit exclusion work while maternity colonies are active, typically April 1 through August 14. During this period, young bats (pups) cannot fly. If adults are excluded while pups are still inside, the pups will die in your walls and attic — creating significant odor problems and potential health hazards.

Legal exclusion windows:

• August 15 – October — preferred window; pups are flying, colony will not return until spring
• November – March — bats are absent or hibernating; full sealing allowed with no risk of trapping

If you discover a colony during the prohibited season, an operator can assess the situation, advise on interim measures, and schedule exclusion for the first legal opportunity.

How Bat Exclusion Works

Professional bat exclusion follows a systematic process:

1. Inspection — The operator identifies all active entry points and assesses colony size
2. Exclusion devices — One-way tubes or netting are installed over active entry points, allowing bats to leave but not re-enter
3. Secondary sealing — All other gaps and potential entries are permanently sealed while exclusion devices are in place
4. Monitoring — After 5–7 nights, activity is confirmed absent and exclusion devices are removed
5. Final sealing — All remaining entry points are permanently closed

The process typically takes one to three weeks depending on colony size and weather. Done correctly, exclusion is permanent — bats will not be able to return to the treated building.

Rabies Risk

Any bat found inside living quarters (bedroom, living room) should be treated as a potential rabies exposure. Do not handle the bat with bare hands. If possible, contain it for testing. Contact your local health department immediately. The Indiana State Department of Health can arrange rabies testing for captured bats.

Less than 1% of wild bats carry rabies, but the disease is fatal once symptomatic — so any direct contact or overnight exposure while sleeping warrants medical evaluation.

Guano Cleanup

After colony removal, attic cleanup is strongly recommended. Indiana bat guano can accumulate several inches deep in a colony that has been present for years. Cleanup typically includes:

• HEPA vacuum removal of all guano deposits
• Antimicrobial treatment of affected surfaces
• Replacement of contaminated insulation
• Deodorization

Some operators handle remediation directly; others subcontract to biohazard cleaning firms. Ask about cleanup services when getting quotes.

Finding a Registered Operator

Indiana requires nuisance wildlife control operators to register with the DNR Fish & Wildlife Division under IC 14-22-38. Always ask for an operator’s DNR registration number and verify it before work begins. This ensures the operator knows and will follow Indiana’s seasonal exclusion rules.

Use our directory to find bat exclusion operators in your county or browse all operators who handle bats.