Bats are fascinating creatures that evoke images of flying mammals swooping through the night sky. But what happens when these nocturnal animals find their way into your home? Where do they go during the daytime hours when they aren’t active? This article will explore the hiding spots and habits of house bats during daylight.
Do Bats Live in Houses?
While we often think of bats living in caves, they will also roost in man-made structures like attics, wall voids, chimneys, and other crevices they can squeeze into. Bats may find access to your home through small openings in the roof, gaps around chimneys, loose vents, or openings where wires come into the house. Once inside, they will look for warm, humid areas to roost in while they sleep during the day.
Some bat species like big brown bats are very adaptable and actually prefer roosting in buildings. But bats that form colonies, like Brazilian free-tailed bats, usually only roost in houses when a colony’s natural roosting site has been disturbed. For example, a colony may relocate to a nearby building if a cave has flooded or their hollow tree has been cut down.
Where Do Bats Hide During the Day?
Bats need a safe place to sleep and hide from predators during their daylight hours. In a house, this often means tucking themselves into narrow crevices in attics, walls, and other hidden spaces. Here are some of the top spots bats may hide in your home during the day:
Attics
Attics offer warm, sheltered spaces that bats love. They can find nooks and crannies in the eaves or between rafters and insulation where they can sleep undisturbed. The warmth from the rooms below also helps keep the attic heated. Large brown bat colonies may gather in attics. Over time, the accumulation of their droppings and urine can cause unhealthy mold and damage insulation.
Wall Voids
Narrow gaps between walls, whether inside partition walls or in the space between interior and exterior walls, provide excellent hiding spots for bats during the daytime. These voids may have openings to allow bats to enter, or bats can sometimes gnaw their way into wall spaces if they smell a good roosting location. Wall voids protect bats from the elements and predators. They’ll squeeze into these cracks and crevices to sleep.
Chimneys
Chimneys make ideal roosting spots because they are sheltered and allow bats easy access to exit at dusk. Bats will cling to the brick or stone walls inside the chimney or tuck themselves into spaces between the damper and the chimney. Chimneys may provide habitation for large numbers of bats that form colonies. The guano and urine can corrode and erode the chimney over time.
Behind Shutters
On the exterior of homes, bats may find access behind shutters or into the gaps where shutters meet the house. They can crawl behind shutters and sleep there safely during the daytime against the warm exterior wall of the home.
Under Sidings and Shingles
Gaps or crevices between exterior sidings, shingles, roof tiles, or trim boards provide shelter for roosting bats during daylight hours. Bats may wedge themselves into these narrow exterior spaces, where they are out of sight and protected.
Between Floors and Ceilings
If there are openings between floors or between ceilings and walls, bats may take up residence in these dark interiors. Attic floors, unfinished basements, and gaps in construction joints give bats access to the space between stories. Openings around pipes, conduit, wiring, and vents also allow them to move within the floor and ceiling voids.
Porches and Patios
The outdoor overhangs of porches and patios can also provide roosting sites if there is access underneath. Bats may find protected areas to sleep underneath the decking or roof. Exposed rafter tails and gaps between trim boards allow them to tuck up into hidden areas.
Trees
Trees that have fallen against the home or overgrown branches touching the exterior walls give bats opportunities to roost during the daytime. Bats may hide in knots, cavities, or cracks in the trunks or large branches. Leaves and vines growing against the house help conceal them.
Habits of House Bats During the Day
Understanding the daily schedule and habits of bats while roosting in your home can help you take steps to evict them humanely. Here are some behaviors and patterns you may notice:
When Do They Enter and Exit?
Bats are only active outside the roost during nighttime hours. They will return to their roosting spot in the house about 30 minutes before sunrise. Often you may see bats exiting around dusk as they leave to forage for food. But in some cases, they may wait for full darkness. Their re-entry times in the early mornings frequently range between 4:00-6:00 am.
Clustering in Roosts
Bats that form social colonies or clusters will congregate together in their shared daytime roosts. In attics and wall spaces, hundreds of bats may pack together tightly. They prefer to wedge into tight crevices. Body heat from clustering helps keep them warm.
Grooming and Interacting
Throughout the daytime, social bats spend time crawling over one another, grooming each other’s fur, and interacting within the roost. They clean and scratch themselves and their neighbors to help control parasites. There may be intermittent squeaking and chattering.
Short Disturbances
Even in daytime hours, bats may occasionally fly out briefly if disturbed by loud noises from inside the roost space. However, they will quickly return to their roost. Bats rarely fly around the interior during the day and may only relocate if strongly disrupted.
Temperature Regulation
Bats allow their body temperature to cool when resting during the day, entering short bouts of torpor. If indoor temperatures rise above 100 degrees Fahrenheit in an attic space, they may become stressed or die. Bats need temperatures between 60-100 F degrees.
Nocturnal Feedings
All bats that roost in buildings will leave their hiding spots from dusk to dawn to feed outside. Their diet consists mainly of insects, so they forage around lights and pools of water that attract bug congregations.
Signs of Bats Roosting in Your House
Suspect bats may be roosting inside your home if you notice any of these signs:
– Bat droppings around the house, especially concentrated piles in attics and walls
– Greasy brown staining from bat gland secretions above rafters and along walls
– Evidence of light scratching, biting, or clawing damage from bats climbing into crevices
– Live bats exiting the house at dusk or entering at dawn
– High-pitched squeaking or chattering noises in walls and ceilings
– A bat-like odor from accumulations of guano and urine
You may also hear scratching, squeaking, or movement noises coming from infested areas during the day. Additionally, dead bats may sometimes be found in the living space if they emerge disoriented from hidden voids.
Potential Health Risks from Bats
While most North American bats don’t pose serious health risks to humans, there are still important concerns to note if bats are roosting in your home:
Bat Bites
Bats don’t often bite people intentionally unless handled, but accidental bites can occur if someone comes into direct contact with a hidden bat. Their sharp teeth usually leave two small puncture wounds. Bats have very small jaws, however, so the bite may go entirely unnoticed.
Disease Transmission
The biggest potential health hazard from bats is disease transmission through bites or contact with their droppings. Examples include:
– Rabies – While not common, bats can sometimes carry rabies. The bat would have to be rabid and then bite or scratch someone for transmission to occur.
– Histoplasmosis – Caused by a fungal spore in accumulations of bat droppings. Can lead to flu-like respiratory illness if inhaled.
– Cryptococcosis – Another fungal disease associated with bird and bat droppings. Affects the lungs and central nervous system.
Guano accumulations in attics, walls, and chimneys raise the risk of spreading these diseases. Bat parasites like bat bugs may also bite people.
| Disease | Transmission Method | Symptoms |
|---|---|---|
| Rabies | Bite from infected bat | Fever, weakness, headaches |
| Histoplasmosis | Inhaling fungal spores | Flu, pneumonia |
| Cryptococcosis | Inhaling fungal spores | Pneumonia, meningitis |
Ectoparasites
Bats commonly have external parasites like mites, fleas, ticks, and bat bugs that feed on their blood. These ectoparasites can sometimes bite other animals (including humans) encountered near the bats’ roosting places in search of a new host.
Evicting Bats from Your House
If you discover bats are roosting in your home, contact a professional bat control expert certified in bat exclusion work. Never try to poison, fumigate, or intentionally harm the bats. Exclusion is the proper method:
Identify their Entry Points
Inspect the interior and exterior of your home carefully to find how the bats are getting inside. Search for small openings in the roof, attic vents, cracks and gaps in siding, openings around chimneys, and loose screens. Note where bats emerge at dusk and return at dawn.
Seal Up Entry Points
Once identified, use materials like silicone caulk, copper mesh, hardware cloth, steel wool, or expanding foam to securely seal up any openings wider than 1/4 inch. This should exclude bats humanely without trapping them inside. It may be necessary to install one-way exclusion devices that let bats escape but prevent re-entry.
Clean Up Roost Areas
Guano and urine deposits should be cleaned from infested attics, walls, and other roost sites once bats have been excluded. Wear proper protective gear when dealing with accumulations of bat droppings, as the spores can be harmful. Specialized disinfectants help eliminate parasitic bugs. Remove any nest-like roosting materials too.
Monitor for Any Remaining Bats
Check for signs of additional bat activity after exclusion work is complete. Ensure all gaps are still sealed properly and look for any bats still exiting at night or entering pre-dawn. Additional exclusion measures may be needed until bats are fully evicted. Annual inspections can ensure your home stays bat-free.
Conclusion
While having bats roosting in your home can be alarming, understanding their behaviors and habits can help resolve the issue humanely. During the day, house bats seek out dark, undisturbed spaces to safely sleep and hide. Attics, wall voids, chimneys, and other crevices offer shelter. Once identified, bat-proofing a home and removing guano deposits can successfully evict unwanted bats and prevent re-infestation without causing harm. With proper exclusion and preventative measures, bats can be safely managed.