Bats are mysterious creatures of the night. When dawn breaks, where do these winged mammals go to sleep through the sunny hours? If you’ve ever wondered where bats hide during the daytime, you’ve come to the right place.
If you’re short on time, here’s the quick answer: Bats roost in dark, secluded places like caves, trees, abandoned buildings, and bat houses to sleep through the day.
In this comprehensive guide, we’ll uncover all the insider details on bats’ daylight shelters. You’ll learn the different types of roosts bats use, the features they look for in prime hiding spots, and how their sleeping habits change with the seasons.
Different Kinds of Bat Roosts
Caves and Mines
Caves and mines are the quintessential places that come to mind when thinking about where bats nest. Around 33% of North America’s bats nest in caves or mines at some point during the year, seeking stable temperatures and seclusion from predators and the elements.
Certain species like the gray bat rely almost exclusively on deep, humid caves as roosting spots. These dark hollows apparently make ideal nurseries to raise their young bat pups, called pups.
Trees and Forests
You might be surprised that over 25 species of North American bats nest in the nooks and cavities of trees during the daytime. Species like Seminole bats often roost under loose bark or in old woodpecker holes lined with moss or leaves in mixed hardwood forests.
Researchers even discovered threatened northern long-eared bats behind peeling bark on an oak tree in New Hampshire! Removal of old trees and dead snags threatens these important forest bat habitats.
Old Buildings and Bridges
Bats sure can find convenient accommodation in structures built by humans! Many species gladly move into abandoned barns, under eaves of houses, or wedge themselves into tiny crevices in old bridges. In fact, over half of the 45 species of bats in the continental U.S. and Canada use human structures for daytime roosting.
Hey, who wouldn’t want a rent-free apartment safe from predators and the elements? Unfortunately, renovations and demolitions can displace entire colonies from these critical roost sites.
Bat Houses
Luckily conservationists came up with a nifty solution to replace lost bat habitats: bat houses! According to Bat Conservation International, over 100,000 bat houses exist across North America. Made from wood, plastic or fiberglass, these boxes mimic hot attics with narrow slits bats can crawl into.
One study tallied over 1,500 big brown bats living happily in a single bat condo in Florida! Installing more bat abodes in backyards helps our furry flying friends keep on patrolling for pesky insects at night.
What Bats Look for in Roosting Spots
Darkness
Bats are nocturnal creatures that sleep during the day, so they require dark spaces to roost comfortably. Their eyes are adapted to low light conditions, so bright environments can disturb their sleep and make them more vulnerable to predators.
Most bats seek out roosts that are sheltered from sunlight, like caves, tunnels, hollow trees, attics, and other man-made structures. Some species, like the big brown bat, will use shutters or siding on houses to create dark crevices.
Darkness provides bats with a sense of safety and seclusion while they rest.
Stable Temperature
Bats need roosts that provide relatively stable temperatures to survive. Since they are small mammals, bats are vulnerable to extreme heat and cold. Their ideal roosting temperature is between 50-100°F. Caves and attics allow bats to find warmer environments in winter and cooler spots in summer.
Bats will often squeeze together in clusters or “bunk” with each other to share body heat. Some bats, like the Brazilian free-tailed bat, will adjust their roosting spots each night within a cave system to find the optimal temperature zone.
The microclimates inside structures protect bats from rapid weather shifts outside.
Seclusion and Security
In addition to darkness and stable temps, bats require secluded, secure spots to safely rear their young. They tend to choose roosts that are isolated from human activity, sheltered from predators, and have enough space for colonies to grow.
Attics, high crevices, and caves offer protection since they limit accessible entry points. Bats often prefer roosting up high, out of reach. Having multiple escape routes is also key for their survival.
Inside dense forests or cliffsides, bats can find many nooks and crannies that provide adequate shelter and seclusion for mating, giving birth, and resting. With plenty of food and water nearby, these safe havens support bat colonies season after season.
Seasonal Changes in Roosting Habits
Winter Hibernation
During the winter months, many bat species in temperate regions such as the United States and Canada enter a state of torpor or hibernation as a means of conserving energy (bats.org.uk). Their heart rates and breathing slow dramatically, and their body temperatures can drop as low as a few degrees above freezing.
Bats may choose underground sites such as caves, abandoned mines, tunnels, and cellars as winter roosting spots. These environments provide stable temperatures and high humidity levels ideal for hibernation.
For example, little brown bats (Myotis lucifugus) and big brown bats (Eptesicus fuscus) often gather in clusters ranging from a few dozen to several thousand individuals on cave ceilings or walls during winter (nps.gov). Their wings wrap tightly around their bodies, heads tucked in to conserve heat.
These bats can reduce their heart rates from up to 1000 beats per minute down to just 25! Such adaptations allow them to survive months without feeding.
Maternity Roosts in Summer
In spring and summer months, pregnant female bats gather in warm, nursery roosts to give birth and rear pups. Attics, barns, bridges, bat houses, and trees all provide suitable shelter. Colonies range from a few dozen to hundreds of thousands of mothers and pups (batcon.org).
The large numbers allow bats to raise temperatures to suit lactating mothers and vulnerable newborns.
For instance, Mexican free-tailed bat (Tadarida brasiliensis) maternity roosts in Texas and New Mexico may shelter up to 250,000 adult females each summer! The high density of so many warm bodies raises roost temperatures to around 100°F (37°C). Such hot roosts speed up the growth rate of pups.
The more quickly young bats grow, the sooner they can fly and feed independently to survive their first winter (tpwd.texas.gov).
In comparison, big brown bat maternity colonies are much smaller, averaging around 135 adults. But these bats choose hot spots too, like attics. Their bodies warming the roost to 80-100°F to aid pup development (dnr.state.mn.us). Choosing the right roost is crucial for reproductive success!
Conclusion
As you can see, bats seek out a variety of hidden, sheltered places to snooze away daylight hours. Their roosting habits meet specific needs for darkness, temperature moderation, and protection from predators and weather.
Understanding where these winged mammals hide gives us insight into their daily rhythms and behavior. It also allows us to support their habitat requirements through conservation of natural roosts and provision of artificial roost boxes.
The next time you come across a hollow tree, cave, or abandoned barn, imagine it filled with sleeping bats! If you listen closely at dusk, you might even hear them stir as the sun sets and night begins—their time to fly.
