Are Bats Nocturnal Or Diurnal? Their Sleep Behavior Explained

Written by Janet F. Murray
Published: October 25, 2022
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Which stories and tales do you know about bats? For many, bats conjure images of Dracula and other fictional blood-sucking creatures. But in reality, bats are gentle animals that play an essential role in our ecosystems. Bats come in various shapes and sizes and live on every continent except Antarctica. Also, while 70% of species feed on insects, many bats eat fruit or nectar. But are bats nocturnal or diurnal? Let’s take a closer look at bat sleep behavior.

Are Most Bats Nocturnal?

FRUIT BAT

Most bats are nocturnal and come out at night to feed.

©Here/Shutterstock.com

Most bats are nocturnal animals. While exceptions to this rule exist, most bats generally hunt for prey at night and sleep through the daylight hours. This tendency links to several factors, including their heightened sensory abilities at night and shifts in cues that mark the passage of time between day and night.

Approximately a dozen bat species are the exception to the rule as they are diurnal (active during the day). However, they only make up a minute portion of the 14,000 bat species. Most are nocturnal, which makes sense, considering that most bats rely on their excellent senses and keen hearing to navigate the dark and locate prey.

Bats are intriguing animals and essential members of our ecosystems regardless of when they are active, making them valuable creatures to study and protect.

Daytime Activity in Nocturnal Egyptian Fruit Bats

Seeing bats flying in the daytime is not common. So you might be surprised to hear about Egyptian bats flying during the day in Tel Aviv, Israel. These Egyptian fruit bats are unlike most other nocturnal bats in several ways. They are often active during the day due to conducive environmental conditions and the ready availability of food sources. Additionally, while they have exceptional vision, they use echolocation even during the day. Moreover, their echolocation does not just help them navigate through their environment. In addition to sight, their echolocation abilities enable Egyptian fruit bats to locate ripe fruit trees among the foliage to feed more efficiently.

How long do Bats Sleep?

bats hanging upside down

Bats spend up to 20 hours per day asleep.

©iStock.com/nymphoenix

When it comes to sleep habits, bats are one of the sleepiest animals out there. Compared with humans, who tend to sleep for an average of 7 or 8 hours per night, bats spend nearly 20 hours of every day sleeping. Whether resting peacefully in their caves by day or flitting about in search of food and mates at night, these remarkable creatures exemplify the benefits of getting plenty of shut-eye.

How Long do Bats Fly Around at Night?

Regarding nocturnal animals, bats are among the most fascinating and misunderstood creatures. While they are often associated with darkness and fear, few people stop to think about how long bats spend flying at night. Contrary to popular belief, bats do not spend the entire night airborne, searching for food. Instead, they typically feed for two hours in a single sitting, two or three times, before returning to their roosts to rest for the remainder of the night. This pattern repeats throughout the year, even during mating season. If you ever encounter a bat flying around late at night, know that it will most likely return to its resting spot soon enough.

Do Bats Sleep in the Same Place Every Day?

Many people are curious about where bats sleep during the day. While it might seem logical that these creatures would find a permanent secluded spot in the woods or hide in a cave, the truth is slightly different. In fact, bats often roost in different places each day, depending on their needs. For example, some bats prefer to make their homes in hollow trees, while others may seek shelter behind hanging tiles or in roof spaces.

Additionally, many bats use caves as roosting locations during certain times when they need moisture and cooler temperatures to thrive. Ultimately, it is clear that there is no one “standard” place where all bats choose to sleep each day. Instead, they are constantly looking for the ideal environment based on their needs at that particular time.

Can Nocturnal Bats See?

Animals that fly – bats

Bats rely on echolocation to navigate their way around.

©Rudmer Zwerver/Shutterstock.com

In the popular imagination, people think of bats as blind creatures. After all, they fly around in the dark and rely on an echolocation system to navigate and find food. But the truth is that bats are perfectly capable of seeing things. Their eyes have more light-sensitive cells called rods to maximize their visual abilities at night.

Moreover, some bats rely on sight during the day despite their nocturnal habits. This ability means that these animals aren’t blind but can use different sensory modes depending on the conditions and their needs at the time. Consequently, the common belief that bats cannot see well is a myth. This myth does not account for the different functional roles of vision for these fascinating creatures.

Are These Mammals Sensitive to Artificial Light?

There is research proving that nocturnal bats are sensitive to light. However, it depends on the type of bat species involved and the light’s particular color and intensity. Studies point towards artificial lighting strongly impacting bat behavior. Still, these effects may vary depending on light color and intensity.

To explore this issue further, researchers conducted experiments to measure the activity of different bat species around light posts with differing intensities and colors. Results reveal that slow-flying bats such as Myotis and Plecotus are sensitive to white and green light. They avoid these lights at higher rates than red or dark areas.

On the other hand, more agile species, such as Pipistrellus, showed no significant preferences for any particular type or color of light. This finding suggests that their behaviors may be less affected by external light factors than those of slower-moving species.

The findings indicate that nocturnal bat sensitivity to artificial lighting can vary. Nevertheless, the results highlight the importance of carefully considering the potential impacts of artificial lighting. The red light did not affect the nocturnal bats, so it is the best option for illumination. This choice of lighting will assist in conserving populations of vulnerable nocturnal bat species.

Do Bats Hibernate?

Animal migration - fruit bat

Some, but not all, bats hibernate during the winter.

©jekjob/Shutterstock.com

Many bats hibernate during the winter months. To properly prepare for this period of dormancy, these animals typically seek out hibernation sites such as caves, tunnels, and attics. These sites protect bats from predators and fluctuations in temperature and humidity. Both these elements are critical for ensuring that a bat’s body remains at the ideal temperature during its deep slumber.

Bats typically enter hibernation sites in late fall and spend several months in semi-torpor. At the same time, their metabolism slows down, and they conserve energy. Some bats even group in communal roosts to share body warmth and reduce general energy usage. Overall, the ability of bats to hibernate is an impressive testament to their unique physiology and helps them to survive even in harsh winter conditions.

Why are Bats most Active at Night?

Bats are most active at night for several different reasons. First and foremost, nighttime is when most insects are out and about in the environment. This phenomenon provides bats with abundant food sources.  Additionally, there is less competition for food at night since other predators are typically sleeping or inactive during this time. Another reason bats are most active at night is because it is safer for them. Fewer predators hunt for food in the dark, so bats have an easier time navigating their environment and searching for prey.

Bats Benefit our Ecosystems

Nighttime offers many advantages that allow bats to thrive across various environments. Significantly, abundant food sources, a lack of competition, and predation are among the benefits that bats enjoy. Additionally, their nighttime behavior facilitates the pollination and reseeding of many plant species. So, bats are essential players in the larger ecosystem of our planet.

Nocturnal vs. Diurnal: What’s The Difference?

Navigate to Nocturnal vs. Diurnal: What’s The Difference? for further information about the nocturnal and diurnal phenomenon in various living creatures.

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The photo featured at the top of this post is © Independent birds/Shutterstock.com


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About the Author

I'm a freelance writer with more than eight years of content creation experience. My content writing covers diverse genres, and I have a business degree. I am also the proud author of my memoir, My Sub-Lyme Life. This work details the effects of living with undiagnosed infections like rickettsia (like Lyme). By sharing this story, I wish to give others hope and courage in overcoming their life challenges. In my downtime, I value spending time with friends and family.

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Sources
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