Bats are nocturnal flying mammals that can take up residence in houses, attics, barns, and other structures. While bats are beneficial creatures that eat insects, their droppings and noises can become a nuisance. Getting rid of bats from your home takes patience and care, as bats are protected wildlife in many areas. This comprehensive guide will provide tried and tested methods for humanely removing bats from houses.

Why Bats Enter Houses

Bats may enter houses for several reasons:

Seeking shelter – Bats roost in dark, quiet areas like attics and wall voids. As natural roosts decline, bats seek shelter in human structures.
Raising young – In summer, female bats form maternity colonies to birth and raise pups. Attics provide warm environments for rearing young.
Hibernating – Some bats hibernate in houses over winter. Cavities in walls and attics provide insulation.
Access to insects – Eaves and attics are prime feeding areas, allowing bats close access to night-flying insects.

While having bats on your property can be beneficial for controlling pests, large colonies in living spaces can create noise, odors and health concerns from droppings. Learning why bats enter can help prevent future colonization.

Signs of Bats in a House

Watch and listen for these common signs that bats have entered your home:

Droppings – Bat guano is dark, grainy and crumbles easily. Look for accumulations of droppings along walls, in attics and under eaves.
Stains – Bat urine can leave yellow-brown stains on walls, ceilings and floors. Staining may be indicative of an established colony.
Sounds – Bats make soft chattering noises. Listen for squeaking and fluttering sounds at dusk as bats leave the roost to feed.
Odors – An ammonia-like odor from urine and guano may indicate a large bat colony in the house.
Movement – Bats flying in and out of the house at dusk is a clear sign. Look for bats exiting under eaves or chimneys.

Regularly inspect the exterior and attic areas of your home for evidence of bat activity. Act quickly once bats are detected.

Dangers of Having Bats in a House

While most North American bats don’t pose a direct threat to humans, there are health and safety issues to consider when bats occupy a living space:

Rabies – Less than 1% of bats carry rabies, but it is nearly always fatal if contracted. Never handle bats.
Histoplasmosis – Bat droppings can harbor this lung infection when disturbed and inhaled. Use respiratory protection when handling guano.
Parasites – Bat bugs are similar to bed bugs and can invade living areas from colonies. Ticks and mites may also be present.
Structural damage – Large amounts of acidic guano and urine can damage ceilings, walls and insulation over time.
Fire hazard – Heat lamps used to treat bats can ignite guano accumulations in walls and attics.

While low, risks do exist when bats occupy living spaces. Act quickly if bats are detected inside the house.

Humane Bat Removal

Most bats are considered valuable natural pest controllers and are protected under law. Lethal methods of bat removal are illegal in many regions. Here are humane options:

One-way exclusion – Bats can exit but not re-enter the roost. Does not trap bats inside.
Deterrents – Devices that annoy bats with lights, sounds or vibrations and cause them to leave.
Sealing entry points – Permanently bat-proofing the home after bats have exited prevents re-colonization.
Wait for young to leave nest – Baby bats are unable to fly. Never seal bats with flightless young inside.
Avoid nursing season – Nursing mother bats should not be disturbed in June and July when feeding young.

With patience and timing, bats can be removed safely and humanely. Contact a professional for large infestations or complex roosts.

When to Remove Bats

Timing bat removal is crucial for both safety and success:

Winter – Bats have lower energy reserves and higher shelter needs. Removal should be avoided.
Nursing season – Mother bats raise young from June to July. Avoid removals during this time.
Early spring – Bats are still in hibernation. Excellent opportunity for exclusions.
Late summer/fall – Young bats can fly and feed independently by August/September. Safest removal time.
Dawn/dusk – Bats return to roosts at daybreak and depart at dusk. Ideal for observing behavior.

Avoid nursing season, winter months, and times when flightless pups may be trapped. Late summer and fall provide optimal timing for safe, successful removals after young bats mature.

Deterring Bats

Various acoustic, visual and air-flow devices can annoy bats and cause them to avoid roosting in a location:

Ultrasonic Repellers

Emit high-frequency sounds uncomfortable to bats but inaudible to humans
Effective initial deterrent but bats may acclimate within 1-2 weeks
Works best in small, confined spaces

Motion-Activated Lights

Bright lights suddenly turned on when bats fly in will startle them
Can be installed at entry/exit points or interiors where bats roost
Bats may avoid illuminated areas or reduce activity

Draft Devices

Small fans blowing air across roosts will deter bats but not exclude them
Air movement interrupts bats’ sense of smell and raises energy expenditure
Fans must run continuously and require an electrical source

Diversionary Roosts

Alternative roosts placed nearby may attract bats away from original site
Can be effective at drawing bats to a new location, especially if old roost is made inhospitable

Deterrents provide temporary relief and work best used in combination before exclusions or permanent sealing.

Bat Exclusion Methods

Exclusion involves sealing bat exit/entry points once it is confirmed all bats have left. Here are exclusion strategies:

One-Way Valves

Allow bats to leave but not re-enter roost
Should be installed at primary exit points in evening once bats have departed
Can be tube-style or flap valves constructed of light plastic, fabric or mesh

Seal Openings After Exits

Observe roost exit points at dusk then seal openings with foam, caulk, insulation or hardware cloth once bats depart
Ensures no bats trapped inside
Can use temporary plugs at first to ensure no re-entries before permanently sealing

Mist Nets

Rectangular netting strung outside roost exit points permits bats to leave but when they attempt re-entry they fall into net
Requires daily monitoring to remove and release trapped bats
Use only for small roosts and supplement with exclusion once all bats removed

Infrared Monitoring

Thermal cameras placed at primary roost exits can confirm all bats have left before sealing
Allows remote 24/7 monitoring with time-stamped footage confirming no re-entries
More expensive but avoids trapping bats inside

Key Exclusion Guidelines:

Seal all feasible exits points
Use proper sealing materials for openings
Continuously monitor with cameras or visual checks for minimum 3-5 days to confirm success and no trapped bats

Sealing Possible Entry Points

Bats exploit amazingly small gaps and crevices to enter houses. Here are key areas to inspect and seal:

Attic vents – Use fine wire mesh to close vents while permitting airflow
Ridge vents – Seal ridge cap end gaps with mesh, caulk or foam
Roof and wall gaps – Inspect where siding, flashing, stucco or bricks meet the roofline. Seal any separations with caulk or foam.
Eaves – Plug gaps around overhangs, fascia boards and soffits with sprays or similar flexible fillers
Chimneys – Seal crevices with steel wool or copper mesh. Never block chimney flues.
Vents and louvers – Protect openings behind attic vents, turbine vents and crawl space louvers with 1/6″ stainless steel mesh.
Doors and windows – Fill gaps around frames with rope caulk, foam or similar flexible, durable sealants. Ensure attic access doors seal tightly.
Around utilities – Seal gaps around electrical, plumbing, cable and gas lines where they meet the exterior with caulk or expandable foam sealant.

Sealing every possible entry after excluding bats is key to preventing future colonies from gaining a foothold.

Remove Droppings and Contaminated Materials

Guano accumulations present health risks from histoplasmosis fungus. Safety precautions include:

Wear protective gloves, eye shields and an N95 particulate respirator
Mist guano with water before removal to suppress dust
Do not use leaf blowers or vacuums which can circulate spores
Place droppings in heavy plastic bags for secure disposal
Clean surfaces with disinfectant or bleach solution
Avoid stirring up dust when removing contaminated insulation or building materials

Proper cleanup after bat removal reduces health hazards for residents. In some cases, professional removal of large guano accumulations may be advisable.

FAQs About Removing Bats from a House

How do you get rid of bats in walls?

Locate entry points and wait for bats to exit at dusk. Then seal openings with silicone caulk, expandable foam, hardware cloth or other durable materials. Bats in walls can often be removed by excluding access back into the roost space.

What smells do bats hate?

Bats have a strong sense of smell. Strong odors of peppermint oil, naphthalene flakes or ammonia can discourage bats from roosting in a space. However, smells alone will not force bats to abandon an established roost. Exclusion techniques are also required.

Will bats leave on their own?

Not usually. Bats are highly loyal to established roost locations, especially during breeding season. And females will not readily abandon young unable to fly on their own. Intervention is typically required to get bats to leave human dwellings and prevent re-colonization.

How do you keep bats from returning?

After full removal and cleanup, it’s critical to seal all possible entrances so bats cannot return and re-establish colonies. Use durable sealants, hardware cloth, steel wool and fine mesh. Continually monitor and maintain seals, as bats will persistently seek ways to re-enter previous roosts.

Can you seal bats in walls?

It should always be avoided. Well-planned exclusions rely on allowing bats to exit before sealing entry points. This is why proper timing, monitoring with cameras and conducting removals in stages is so important – to ensure no bats become trapped inside walls or the structure.

Conclusion

Removing bats from houses requires understanding bat behavior patterns and biology in order to time interventions safely and effectively. While humane exclusions and sealing can successfully eliminate indoor colonies, patience is required. Persistence and rigorous monitoring are also vital, as bats will make every effort to re-enter previous roosts in human dwellings. By following best practices and avoiding nursing season and winter months, bats can be safely removed from houses and prevented from re-colonizing without harm. A coordinated approach enlisting qualified bat removal experts when necessary will result in successful elimination of unwanted bats while still respecting their ecological importance.

How to Get Rid of Bats in a House