Why Bats Will Leave On Their Own (And What To Do If They Don’t)

Bats are fascinating, often misunderstood creatures that are essential characters in our shared environment. Sometimes bats will occupy places where they aren’t welcome though, and you may find yourself wondering whether they will leave on their own, or if you should take steps to remove them.

A single bat in your home will often leave with minimal intervention, but a colony of roosting bats could be harder to remove and will often return year after year. You’ll most likely find bats roosting in your attic or in a crevice of your home in which you should call a professional for removal.

There are many instances where bats will leave on their own, but often removal of a colony of bats will require some effort. You should avoid physical intervention because of the risk to both yourself and the bats, making exclusion the best method. Read on to discover why bats may leave on their own, and what to do if they don’t!

Will Bats Leave On Their Own?

The most pressing question you may be asking is whether or not bats will leave on their own, and the answer is, sometimes. There are two types of bat infestations that are likely to affect your home, and they will have different impacts and removal methods. 

A single bat in your home likely got there by mistake and is probably as desperate to leave as you are to remove it. Bats can get into cracks as small as about an inch and a half by a quarter inch, that is tiny! 

A single bat in your home is most likely lost and confused, and you can remove them with minimal intervention by simply opening the door. However, a roost of mating or hibernating bats in your attic will be much harder to evict.

Just remember, if you’re having a bat infestation to contact professional help immediately.

Bats Tend To Leave Their Nest Area Nightly

Bats are nocturnal hunters who feast on insects that are active at night, such as moths. Because of this, they will leave the nest or roosting site every night to search for food.

While bats are out looking for a meal and socializing at night it’s the best opportunity to seal off any areas they may be used to sleep the day away. 

Keep in mind that bats are sensitive to cold, and many will hibernate or migrate during the winter. This means that bats will be active at night during the warmer months, but over the cold winter season, bats will remain in their roost until the weather warms again. 

Avoid waking a hibernating bat to remove it at the risk of harming the bat. Waking a hibernating bat will drain much of its energy and can harm the bat or even prevent it from surviving until spring.

Be mindful that most states have individual laws protecting certain species of bats when they’re roosting. So if you’ve got roosting bats in your home, do some research on the local regulations on bat exclusions.

Bats Won’t Stay In A New Spot Unless It’s Perfect

Bats are social animals that are highly sensitive to temperature, sound, light, and smell. These sensitivities make the bat picky about where it will choose to stay.

Bats require a nesting site that is protected from weather and is dark and warm during the day while they sleep. This is where we get the common trope of bats in caves. With increased urbanization and habitat loss, bats have to seek these same conditions elsewhere.

These habitat needs are why man-made structures are so appealing to many bats in more developed areas. For example, an attic provides a protected space that stays warm, dry, and dark throughout the day.

Disturbances to their habitat will cause a bat colony to seek shelter elsewhere. We will talk about ways to make your own home less appealing to bats later on.

Bats Will Return To The Same Nesting Site Year After Year

Because bats spend so much time finding an ideal roosting site, they are likely to return to it again and again. In fact, the Maine Department of Inland Fisheries and Wildlife cites banding studies show that bats migrate around 120 miles between summer and winter sites, and still occupy the same roosts each year. 

Bats have highly sensitive noses which they use to find their roosts each night, and they use their sense of smell to identify past nesting sites.

Exclusion is the best way to prevent bats from returning to your attic at the end of a long migration, so it is important to identify their entry points while they are still present in your area in order to ensure they can’t come back.

A thorough cleaning is important both because of the germs that bats can spread, as well as to eliminate the odors they are leaving behind that are attracting them back to the area.

What Is Attracting Bats To Your Area?

A big part of bat infestations has to do with why they are attracted to your home in the first place.

There are two main types of bats, those who feed on fruit and those who feed on insects. You are much more likely to find insect-eating bats in developed areas because of the abundance of food available.

Check out our articles about what’s attracting bats to your home or what’s attracting bats to your backyard for more individualized information.

Open Landscapes Or Water Can Attract Bats 

Most typically, bats will congregate around areas of water, caves, cleared forest land, habitat boundaries, closed crevices, and open grasslands.

Habitat loss and fragmentation lead bats and other animals to get more creative in their nesting sites and food acquisition.

Agricultural fields and pools mimic grasslands and natural bodies of water in developed areas. Streetlights are another common place you will see bats.

You may have also noticed their fast movement under streetlights at dusk, darting back and forth under the light. Growing up, we had a huge light post in our yard where we would typically see this!

Abundant Insect Populations Attract Bats

What these places all have in common is an abundance of insects.

Bats are attracted to any areas where insects swarm in large numbers, which looks different depending on whether the land is developed or natural. After all, its how they eat!

Insect populations are also much more active in the warmer months because their tiny bodies don’t tolerate cold weather. This is another reason why you will notice more bats during the spring and summer before they hunker down for the long winter months.

Warm Dark Spaces Make Ideal Roosting Sites

Bats require shelter when they are inactive during the day. In the wild, they will roost in large trees, deep in the canopy, or in caves.

Habitat loss can make it harder to find these types of environments, which is why urban bats commonly choose man-made structures to make their homes.

Outside structures like sheds and carports look like a great substitute for a cave to a colony of bats searching for shelter. Attics are another common site that serves a similar function to a cave or other dwelling.

Your attic is warm, dark, and protected from wind and rain, and bats are able to squeeze through the smallest of cracks in order to reach the safety of your home.

Why It Can Be Nice To Have Bats Around

Bats have often been misunderstood creatures, due to the fear of germs that they can spread. While these threats are present and you should definitely be careful not to touch or scare a bat, they still play an important role in our environment and can be good to have around. 

Bats Are Good Pest Control 

The biggest and most obvious benefit to having bats around is pest control. Pennsylvania State University states that just one bat can consume up to 3,000 insects per night. That is three times their body weight!

Without bats, many insect populations would skyrocket out of control. That many insects would also wreak havoc on our crops, consuming tons of food and squandering the resources put into farming.

Because of the role they play in the ecosystem, bats are actually protected by many laws that prohibit harming individuals or colonies. Keep reading to discover the best humane ways to get bats to leave you and your home alone.

Why Will Bats Leave On Their Own?

There are many reasons that bats may leave their nests, but keep in mind that they are likely to return to a roosting site with an abundance of resources available. Let’s look at a few reasons why bats may choose to leave a site on their own below!

Competition For Habitat Will Drive Them Away

In a study by the University of Tennessee, competition is listed as one of the main reasons why bats might leave an area or choose not to roost there.

Because they live in colonies of such large numbers, the availability of suitable roosting habitats is an essential factor in how they choose a home. 

There are many invasive and native competitors that will drive bats away from an otherwise suitable roosting site. These species can include birds, tree frogs, and insects such as ants and beetles.

If a bat feels threatened or crowded out by these competing animals, they are likely to move on to a new less occupied space.

They Will Eventually Want To Look For Other Food Sources

Another reason that bats may leave on their own is if they run out of their food source. This can happen for a few reasons.

Pesticides and insecticides applied to agricultural fields can eliminate the bat’s food source, as can at-home insect mitigation methods. Harsh weather can also hurt insect populations, which can’t withstand extreme cold, rain, or wind.

Bats can also be too effective or populous, eating enough of the insect population that it struggles to rebound.

Whatever the reason, if the food is gone, the bats are likely to follow.

Bats Leave Areas That Are Unsafe Or Irritating

Another reason that bats may leave an area is that they feel unsafe or are disturbed by other factors in the landscape. 

Predation is a quick way to make a bat feel unsafe and get it to move on from an area. Owls, hawks, and snakes are common predators of bats around the world. These predators will quickly drive a bat colony from their roosting site because of the threats they pose to baby bats.

Other irritants to bats are lights, sounds, and smells.

Bats are highly sensitive and will only stay at sites that meet their needs. You can use this to your advantage when trying to exclude bats from your home, which we will touch on a little bit later!

Many Bats Migrate

There are many species of bats that will migrate during the cold winter months, which is a great time to seal off any areas that they may be used to enter your home.

Some species of bats will migrate up to hundreds of miles from their summer homes to the warmer climates in the southern hemisphere.

However, other species of bats will stay behind and hibernate.

Remember that hibernating bats are especially sensitive to the energy loss of being repeatedly woken, and make sure to not to seal off the area before they are ready to leave in the spring. 

What To Do If Bats Don’t Leave On Their Own

Typically, it’s against the law to use baits to get rid of bats.

The best way to remove bats is exclusion. This means waiting until the bats are out of the roost and using methods to prevent them from re-entering.

Timing of exclusion is important to the protection of bats, and you should try to use the following techniques between the hibernation period and when babies are born in spring, or after the young are independent in late summer to early fall. Consult a local wildlife control pro in your neighborhood to make sure you’re taking action at the right time!

Annoy The Bats Out Of Your Space

We went over the pickiness of bats in choosing a site for roosting and raising young, and you can use their sensitivity to make your own home less comfortable, ultimately driving them to seek shelter elsewhere. 

If bats have taken shelter in your attic or another structure on your property, the University of California suggests many techniques to create an uncomfortable or harassing environment for bats, including cold, light, and noise to drive them from the area.

Set up a fan or cooling system in the roosting space. Bringing the temperature down will make the space uncomfortable for the bats, especially for their young who are born hairless and less able to regulate their body temperature.

Similarly, you can illuminate the space with a floodlight like this Samyoung Lumen Worklight and keep it running daily hours a day to drive the bats from the site.  

Give Them Other/Better Places To Live

Another way to get bats to move on from your home is simply to give them a better option. Bat boxes are an easy way to give bats an appealing alternative roosting site you actually want them to use.

A benefit of installing bat boxes is that you still get all of the positives of having bats around like pest control and natural biodiversity, but you don’t have to give up attic space for it.

Building a bat box could be a fun weekend project to take on, or you can purchase one like this Kibaga Ultimate Wooden Bat House. If you do choose to DIY it, make sure to do your research to meet the unique needs of bats.

Once you install these boxes, it might take time for the bat colony to recognize and utilize them, so the harassment techniques we discussed before will still be useful in making the boxes look more appealing.

Seal Off Entrances When They Leave At Night

When the bats leave the roost to hunt at night is the best opportunity to seal off any holes or cracks they are using to gain entry.

Around dusk, when the bats make their exit, station some friends and family members around the home to identify exactly where the holes are.

Keep in mind the time of year when sealing these holes. Baby bats are flightless from when they are born in May through July, and barricading the adults outdoors will leave them trapped inside your home, cut off from parental care.

You don’t need to worry about bats chewing or gnawing their way back inside once you successfully exclude them. If their entrance is cut off, bats will simply move on to a new site. 

Install A One Way Door 

There are a few different types of one-way doors, but all of them will work the same to get bats out. Once you identify the entry holes, there are many options to install a trap door that will allow the bats to exit your home, and prevent them from re-entering. 

Most typically these options include a quarter-inch mesh wire attached to the wall with only the bottom detached so that bats can find their way out, but cannot reenter.

Another option for walls or other surfaces that aren’t horizontal is something like this Batcone Reusable Bat Exclusion. Tubes like this have a flap that lets the bat leave but will fall down over the entry point to exclude the bat.

Use Repellents And Strong Scents

Bats have an excellent sense of smell, which they use to find a suitable roosting site and locate it each time they return home.

You can use their sensitivity to smells to your advantage by utilizing smells that repel bats like peppermint or eucalyptus. 

You can use Bonide Magic Bat Repellent which contains those scents and other ingredients, or you can even use essential oil-soaked cotton balls placed strategically around any entry points or in roosting sites.

For a complete list, check out our article on scents that bats hate.

Leave A Door Open For Bats To Escape 

Occasionally, you might see a single bat who has entered your house by mistake.

These are usually juvenile bats who have entered your home by mistake and are likely just as desperate to escape as you are to kick them out. 

If this happens, the best thing to do is remain calm. Distressing the bat further by coming at it with a broom or wildly waving your arms and screaming will make the bat panic and become erratic in its movements. Instead, close off access to other rooms by shutting doors and confining it to as small a space as you can manage.

Then, open a door or window and shut off the lights inside to better direct the bat toward light coming in from outdoors. 

If you provide the opportunity for escape, the bat is sure to take advantage, slipping out of the open door or window to freedom. 

Never touch the bat with your bare hands, utilize gloves and keep as much distance as you can between yourself and the bat to prevent contact, and always contact a health professional if you suspect you may have had contact or been bitten by a bat. 

Quick Recap!

To recap what we’ve learned, bats are remarkable and important creatures that play an essential part in our ecosystem. Habitat loss and fragmentation have pushed many bats to seek shelter in unlikely places, sometimes including our homes.

While bats will sometimes move on of their own accord, there is a good chance that a roosting colony of bats will return to the same roosting site year after year. However, there are many steps you can take to encourage these bats to move on and prevent them from returning.

• Use harassment techniques such as fans, light, and ultrasonic noise machines to make the site uncomfortable for the bats.
  
• Install bat boxes to give the bats a more appealing place to roost.
  
• Use their nocturnal hunting schedule to time when you will seal entry points and prevent the bats from getting back inside.
  
• Use repellents and other strong odors like peppermint and eucalyptus to repel the bats from the site.
  
• Simply leave the door open with the lights off to give a confused individual bats a chance to leave. 

Thanks so much for reading!

References: 

Caragh, G. Threlfall, B.L., Banks, P. (2013) Roost selection in suburban bushland by the urban sensitive bat Nyctophilus gouldi. Journal of Mammalogy. 94.2, 307–319.

Dodds, M., Bilston, H. (2013) A comparison of different bat box types by bat occupancy in deciduous woodland, Buckinghamshire, UK. Conservation Evidence. 10, 24-28.

Willis, C.K.R., Brigham, R.M. (2007) Social thermoregulation exerts more influence than microclimate on forest roost preferences by a cavity-dwelling bat. Behavioral Ecology. Sociobiology. 62, 97–108.

Loeb, S.C., O’keefe, J.M., (2006) Habitat Use by Forest Bats in South Carolina in Relation to Local, Stand, and Landscape Characteristics. Wildlife Management. 70.5.

Bouvet, A., et. al. (2016). Effects of forest structure, management and landscape on bird and bat communities. Environmental Conservation, 43.2, 148-160.