During winter, we enjoy curling up on the couch with a warm blanket. When it comes to bats, you might find that these creatures aren’t too different from humans. (Just think of their wings as their own personal blanket!)
While some bats hibernate, others migrate! This winter season you might find bats resting in caves, mines, rock formations, tree hollows, warehouses, barns, attics, and basements. While hibernation spots will vary by bat species, most will seek out a predator-free area that has lots of food.
Let’s take a look at how bats act during the winter months, where they go, and how you can help secure your home from unwanted bat activity.
Bats That Hibernate During Winter
According to the National Park Service, when bats hibernate, their body temperature can drop to near freezing and their heart rate drops to about 10 beats per minute. That means that they can go minutes without taking a breath!
Of course, other bodily functions also slow down to help conserve energy. This state of being is called torpor.
During their hibernation, bats will cycle through periods of torpor. This means that they may enter the state of torpor for just a few hours on an especially cold day, or they might stay in torpor for months!
When bats are looking to decide where they should make their home for the period of time that they will be in torpor, they look for places that have an ideal temperature and humidity to properly hibernate.
The ideal hibernation temperature for bats is usually between 35 and 40 degrees Fahrenheit, which is why outdoor places like caves and mines are ideal.
But be sure to keep an eye out, because even high-ceiling buildings can become home to bats during the winter months!
So whether you’re a go-getter who enjoys spelunking during winter or is just trying to clean out your attic this winter season, keep an eye out for bats that might be hibernating in these areas.
Let’s take a closer look at a few common bats that hibernate during winter!
Which North American Bats Hibernate Or Migrate?
|BAT NAME||MIGRATES OR HIBERNATES?|
|Big Brown Bat||Hibernates|
|Little Brown Bat||Hibernates & Migrates!|
|Northern Long-Eared Bat||Hibernates|
|Eastern Pipistrelle (Tri-Colored Bat)||Hibernates|
|Eastern Red Bat||Migrates|
|Silver Haired Bat||Migrates|
Big Brown Bat
The Big Brown Bat can be found in nearly any type of habitat across North America. From deserts to meadows to forested areas, this bat can also be found in the suburbs where humans and agriculture intermingle.
These bats range in color from light to dark brown and have black on their ears, nose, and wing membranes. One of many insect-eating bats, this bat weighs less than an ounce but has an impressive wingspan that can range in length from 12 to 16 inches!
Big Brown Bats will hibernate during the cold months of winter, but because of their size, they can remain fairly active at lower temperatures compared to other bats.
Big Brown Bats will hibernate in caves, tree cavities, and even man-made structures like your home, most likely in your attic or wall voids.
Little Brown Bat
I know it seems far-fetched: first a Big Brown Bat and now a Little Brown Bat?
Yes, as its name might suggest, this bat is smaller than our first mention, but these two are in fact very different species of bats.
While generally brown in color, this bat can also display reddish coloring. Weighing in at less than half an ounce, its wingspan is less than a foot, generally between 8 and 11 inches in length.a
During the winter months, Little Brown Bats will hibernate in caves and mines because of their constant temperature.
Surprisingly, this bat has been known to migrate as well between their winter caves and more well-suited summer habitats.
According to the Wisconsin Department of Natural Resources, this migration may allow for the bats to move between their roosts and feeding ground but may also be to help protect themselves from seasonal predators.
Northern Long-Eared Bat
The Northern Long-Eared Bat can be distinguished by– you guessed it– its long ears!
Definitely one of the smaller bats from those we’ve mentioned, this bat weighs in at about a quarter of an ounce and has a wingspan of approximately 9 inches.
This bat is generally light brown in color and lacks the darker spots on its face like some of the other species we’ve mentioned. It’s also an expert at picking off moths and other insects from forests once the sun goes down.
During the warmer months of the year, Northern Long-Eared Bats will roost like many other species of bats and then come fall will move to caves to hibernate.
While this bat will hibernate with bats of the same species, it’s not unheard of for these bats to co-hibernate with other species of bats during the winter months—sometimes up to numbers in the hundreds!
Eastern Pipistrelle (Tri-Colored Bat)
The Eastern Pipistrelle is a yellowish-colored bat but can have varying degrees of coloring from pale yellow to almost an orangish brown. Because the individual hairs on this bat are tri-colored, this is where this bat gets its more well-known name, the “Tri-Colored Bat.”
These bats prefer to roost in forested areas and near waterways so that they’re in closer proximity to the insects they prefer to snack on during the evening hours.
Tri-Colored Bats will hibernate in caves and crevices during the colder months of the year, but if they can find their way inside your home, your basement would make another attractive hibernaculum.
Like many species of bats that hibernate during winter, these specific bats will seek out locations that have a steady temperature of about 40 to 50 degrees Fahrenheit, high humidity, and little to no human disturbance.
Bats That Migrate During Winter
We’ve all heard of birds flying south for winter. It’s easy to see why some bats would do the exact same thing!
There are several species of bats that will move between summer and winter habitats so that they can avoid the cooler temperatures and wetter weather that come along with the winter season.
Other than the temperature itself, a steady food source can be a huge contributor to many bats’ migration, and other bats might also be seeking a more ideal place to raise their young during the winter season.
Because it’s difficult for bats to survive during the winter months, they use migration as a tool for survival to ensure that they and their young can thrive once spring brings warmer temperatures.
Let’s take a closer look at a few common bats that will migrate this winter season!
One of the more unique bats on our list, the Hoary Bat can be identified by its distinctive coloring. These bats have a gray to brown colored fur base, but the tip of their fur is white, so people often consider them to look “frosted.”
These bats can typically be found in forests, but they’ve also been spotted in trees along city or urban parkways.
Hoary Bats will migrate in early fall, usually September and October, to their preferred wintering grounds, and then once spring comes they’ll return home.
During the winter months, you’re most likely to spot these bats in the southern and southwestern regions of the United State but they’ve also been spotted as far south as Central America.
Little Brown Bat
I know that we mentioned the Little Brown Bat in our hibernation section, but this bat can handle winter in several different ways depending on the temperature of their summertime habitat location.
Depending on where this bat roosts, and more specifically how near or far these roosts are to warmer temperatures, the Little Brown Bat might just make the trip and migrate to a warmer environment during winter.
Eastern Red Bat
The Eastern Red Bat is a tree bat that sports reddish-orange fur. This coloring is usually spotted in males, whereas the females are generally grayer in color. No matter the sex of the bat, it’s common for this species to have white patches of fur on their shoulders too.
These bats can be located across the United States, so while the bats that live in the Southern states may remain there year-round, those that live in the Northern part of the US will travel southward for the winter months.
Once the Eastern Red Bat arrives at warmer temperatures, some bats will remain active while others will use the time to hibernate.
You can spot these bats hanging from tree hollows and other parts of the tree. Because of the unique coloring of their fur, the Eastern Red Bat blends in well with tree leaves during the cooler months when the leaves begin to change color.
Silver Haired Bat
According to Texas Parks and Wildlife, the Silver Haired Bat is one of the most abundant bats in forests across the northern United States.
By far the hardiest bats on either of our lists, these bats have black fur with silver tips, and, unlike many other bats, they don’t have any additional, contrasting markings or coloring. Their ears are also furless!
During winter, the Silver Haired Bat will migrate to regions with a warmer climate and then hibernate.
From wood piles, cave entrances, and even buildings, any of these spots could become potential winter hibernacula for these bats.
While these bats are one of the slowest flying bats in North America, because they roost and travel in well-covered areas, they’re rarely in short supply of their favorite insects which include moths, beetles, mosquitoes, and more.
To learn more about bat migration and hibernation, check out
Bats Sometimes Stay Put In The Cold
While migration and hibernation are the most common options for bats during winter, depending on where the bats have made their roosts, they might just stay in the same place all year long.
For instance, bats like the Eastern Red Bat, which already reside in the Southern United States, are likely to remain in the region for the entire year because of the mild temperatures.
Don’t forget that bats, like many other animals, are driven by their food source and shelter. So, if bats are in an area where insect activity and outside temperatures are consistent throughout the year, bats are happy to stay put.
If you live in an area where bat activity is common during the year, in addition to trees and rock formations, non-migratory bats are more than willing to make their way inside buildings if the opportunity presents itself.
Where Can You Find Bats During Winter?
No matter which options bats choose for the winter months—hibernation, migration, or simply staying put—the places that bats decide to stay for the colder months of the year have three major things in common:
- An ideal temperature
- Access to their food source
- Protection from predators
Without further ado, here are eight places you might find bats this winter!
If you’re looking for places that bats can enter your home, check out our piece on the ways that bats get into your house.
Bats Live In Caves
Even though the temperature is a bit colder than you might find comfortable, caves are perfect for bats. Rather than searching for the warmest temperature possible, bats prefer consistency.
You can expect to find bats in caves year-round, but especially in the winter!
Bats Spend the winter in Mines
While a cave is a natural structure in the earth, mines are created by humans. Bats don’t mind, though!
You’re more likely to find bats in closed earthen mines rather than open pits. Also, abandoned mine shafts are more attractive to bats than those that are bustling with human activity.
A mine that has been closed off isn’t likely to be traveled by humans, but snakes and other predators can still find their way in.
bats spend time in Trees
Trees often have nooks and crannies that bats can hide in. Even if your tree isn’t hollow, there are hiding places among the bark and branches.
It’s not a foolproof hiding place, as bats that roost or hibernate in trees and tree hollows may fall prey to hawks and raccoons. But it’s better than being alone in the cold!
If you want the bats gone from your wooded areas, here are the best ways to keep bats away from your trees.
bats winter over in Rock Crevices
Rock crevices are dips and cracks in large stones. Although it is not enclosed like a cave is, it can still give some shelter. A bat will view this as better than nothing!
If you want bats in your yard (perhaps to help control mosquitos and other pests), rock crevices are not the most effective way to attract them. Try something like this Kenley Bat House for Outdoors – Bat Box Shelter with Large Triple Chamber.
bats can be found in Rock Formations
When it comes to providing the ideal temperatures, areas like caves, mines, and even rock crevices offer a certain amount of protection from the elements.
Whether it’s keeping the cold, wet snow out, or providing a more stable temperature that isn’t as impacted by the wind, these locations offer a more stable environment with an ideal temperature for bats to hibernate.
Guaranteeing protection from predators while outdoors can pose a challenge since the bats are more exposed, but some of these areas do offer greater protection from certain predators and other disturbances than other areas.
If you’re an outdoors adventurer, no matter the season, be mindful of your travels during the winter months to not disturb any hibernating animals. If you do encounter a bat during your outdoor travels this winter season, it’s best to leave the bat alone and continue your business (or better yet, leave the area completely).
Bats Can Nest In attics
Since an attic is indoors, it automatically has the boxes checked when it comes to providing an consistent temperature and protection from predators.
However, even though this is a part of your house you likely do not frequent, that does not mean you want bats to move in! Here’s how to keep bats out of your attic for good.
Bats Even Like basements
If you think about it, a basement is kind of like an indoor cave. This is very attractive to bats, even though it may take some work to fly into it!
If you have bats in your basement, try the Neatmaster Ultrasonic Pest Repeller Electronic Plug In. It emits a high pitch sound at a frequency that humans cannot hear. It will make your home far less attractive to bats!
Bats Love barns, Warehouses, and other exterior buildings
Whether it’s your main residence or another outdoor building, these locations will provide protection from freezing temperatures, winter precipitation, and all of the other nasty weather elements that come along with the season.
At this point, if the bat was able to gain access to an interior location, they will certainly have access to get back outside to feed. Whether it’s through an opening in the ceiling or wall, these creatures have an uncanny ability to make their way inside if the opportunity is available.
It’s important to keep in mind, that often bats will leave on their own. (Here’s what to do if they don’t).
How To Protect Your Home From Bat Activity This Winter
Even if you don’t use your attic or basement, having bats in your home probably isn’t your ideal situation.
Before winter settles in for good, consider inspecting the roof and siding on your home and other buildings on your property for any cracks, gaps, or openings.
If you spot a hole or another opening that is any larger than roughly half an inch, the opening is large enough for a bat to gain entry.
Unfortunately, once bats are able to make their way inside, it’s a challenge to get them out. I recommend reading our piece on what attracts bats to your yard, as prevention is key for bats here.
The bats may not come and go at the same time, so sealing potential entry points becomes a large issue since it’s difficult to determine whether you’re sealing the bats in or sealing them out.
In this situation, prevention is the best management tool, but if you do find a bat inside, don’t panic!
When in doubt, or if you find yourself with an entire colony of bats inside, never hesitate to contact your local pest professional for assistance in eradicating bats from your home for good.
You can also read our guide on the scents that bats hate which can help to confuse them thus, keeping them away from your yard.
Putting It All Together
Bats are great at helping to maintain insect levels in the environment, but during the winter months they can cause unwanted disturbances to homeowners if they find their way inside our homes.
For bats that are familiar with urban living, and even those that are accustomed to agricultural or mixed-used areas, bats will actively look for places to hibernate come mid to late autumn.
Be sure to check the areas around your roof – including your chimney – for possible entry ways into your home and close them off before winter settles in. If you happen to come across a bat outdoors in a tree or nearby rock formation though, it’s best to leave the bat alone in its natural habitat if they aren’t causing any harm to yourself, your family, or your property.
Avery, M. I. (1985). Winter activity of pipistrelle bats. The Journal of Animal Ecology, 721-738.
Brigham, R. M. (1987). The significance of winter activity by the big brown bat (Eptesicus fuscus): the influence of energy reserves. Canadian Journal of Zoology, 65(5), 1240-1242.
Hedenström, A. (2009). Optimal migration strategies in bats. Journal of Mammalogy, 90(6), 1298-1309.
O’Farrell, M. J., Bradley, W. G., & Jones, G. W. (1967). Fall and winter bat activity at a desert spring in southern Nevada. The Southwestern Naturalist, 163-171.
Turbill, C., & Geiser, F. (2008). Hibernation by tree-roosting bats. Journal of Comparative Physiology B, 178(5), 597-605.
Whitaker Jr, J. O., & Rissler, L. J. (1993). Do bats feed in winter? American Midland Naturalist, 200-203.
Zack is a Nature & Wildlife specialist based in Upstate, NY, and is the founder of his Tree Journey and Pest Pointers brands. He has a vast experience with nature while living and growing up on 50+ acres of fields, woodlands, and a freshwater bass pond. Zack has encountered many pest situations over the years and has spent his time maintaining and planting over 35 species of trees since his youth with his family on their property.
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