Bat Facts

Bats ['bătz]

A small furry mammal that flies.

Bats: Facts

Vampire Bat Desmodus rotundus

When you think of bats, what comes to your mind? A lot of people think bats are creepy because they only come out at night, roost in dark caves, and are associated with legends about vampires. But bats are not really scary at all. Despite the myths, bats are not blind, will not suck your blood, and won't become entangled in your hair. The truth is, bats are amazing creatures that benefit the earth in many ways. Let's find out more.

Bat Basics

flying natterers bat in forest

Bats belong to an order of animals known as Chiroptera, meaning “wing hand.” Bats, although they can fly, are not birds. They are actually mammals, the group of warm-blooded animals that give birth to live babies, produce milk to feed their young, and have fur or hair. Bats are the fastest mammals on earth and the only mammals that can fly.

Fossils of ancient bats have been found which indicate that bats have been on earth for at least 50 million years. Today, there are over 1,400 different species of bats. There are more species of bats than of any other mammals -- one-quarter of all mammals on Earth are bats! Bats are found on every continent except for Antarctica. Their many adaptations have allowed them to live and thrive almost everywhere.

Bats come in all different sizes. The tiny bumblebee bat, whose body is about the size of your thumb, weighs less than a penny and has a full wingspan of six inches. The largest bat, on the other hand, is the flying fox bat with a wingspan of six feet! Large bats, known as megabats, are long-nosed vegetarians found primarily in the tropics. Microbats are smaller insectivores found all over the world.

Bat Wings

NPS Bat Mine Shaft - LAKE

Bats are the only mammal that can fly. They can accomplish this because of their powerful wings which are very similar to human hands. Their wings are formed by skin which is stretched over four extremely long finger-type bones. They even have thumbs. Besides flying, bats use their wings for grasping and holding on to food and their young.

Bat Habits

Mexican free-tailed bats

If you look up at the sky around the time the sun is going down, you might see bats flying. At first, you may think they are birds, but as you watch you may notice that they don't glide like birds; rather they fly in a more erratic pattern.

Bats are nocturnal. During the day they sleep in roosts such as caves or trees. Depending on what is available in the area where they live, bats have been known to roost under bridges, in buildings or barns, under logs, within abandoned mines, inside hollow tree trunks, and even under large palm tree leaves. They hang upside down from claws on their feet, often in large groups called colonies. Some colonies can have thousands or even millions of bats!

Bats huddle together for warmth and safety, but colonies are also social communities. Sometimes, when a bat is injured or ill and cannot hunt for its own food, other bats will bring food back to it. Within the colonies, bats like to groom themselves and each other. Like cats, they lick themselves thoroughly to keep themselves clean, all while hanging upside down.

flying fox bat

Hanging upside down in a high location puts bats in an ideal position for takeoff. From their elevated position, they drop straight into flight. It also helps them hide from danger. Bats are hunted by owls, hawks, snakes, and other carnivores. By roosting during the day in high, hidden locations, bats are safe from most daytime predators.

When dusk falls, bats awaken and leave the roost to search for food. A large colony of bats emerging from a roost is one of nature's amazing sights. Bats' flexible wings allow them to quickly maneuver through caves and trees in remarkable ways. In fact, bat flight is so acrobatic and complex that it provides a model for engineers who design aerial robots. Bats are the fastest of all mammals. They often fly at speeds of 60 miles per hour and at heights of 10,000 feet. The Mexican free-tail bat can fly 100 miles per hour over short distances.

During the winter when temperatures are low and food is scarce, some bats enter into a state of hibernation. Hibernating bats conserve energy by slowing their heart and breathing rates and lowering their body temperature. Other bat species follow an annual migration, traveling to cooler climates in the warm months and warmer climates in the cool months. Some tiny bats have been known to migrate as far as 1,500 miles!


Swarm of insects

Different species of bats have different food tastes. The greatest number of bats feast on insects. A single bat typically eats over 3,000 mosquitoes in one night, while the little brown bat routinely consumes 1,200 mosquitoes in just one hour! Some bats, mostly in the tropics, eat fruit or sip nectar. Other kinds of bats eat small rodents, birds, frogs, lizards, and smaller bats. A few bat species fish for their dinner by flying over the water and snatching up fish. A very small number (only three species out of 1,400) feed off the blood of animals such as cows, horses, and birds by puncturing their skin with their fangs and licking the blood from the wound. Known as vampire bats, they are found in Mexico and Central and South America.

Baby Bat Pups

bat nursery roost

Most bat species give birth to only one baby per year. Although bats usually have only a single infant, occasionally twins are born. Infant bats are known as pups. Pups can be born weighing up to one-third of their mother's weight.

Infant bats are very small when born and require the care of their mother for food, warmth and protection. Like all mammals, the mother produces milk for the newborn pup. The pup clings to the mother during roosting and could die if it lets loose and falls. When the mother bats leave the nest to find food, they count on the fact that the pups from all the other mothers will huddle together for warmth and safety. Upon the return of the mothers, infants and mothers will quickly locate each other through smell and voice recognition. Baby bats grow quickly and can usually fly by the end of their first month.


bat echolocation diagram

The expression “blind as a bat” is a myth; bats are not blind. Large megabats such as fruit bats search for food using sight and smell. However, microbats who hunt insects mainly find their way around in the dark through a system known as echolocation. They produce high-pitched squeaks, often not audible to human ears, which bounce off of objects like an echo. By hearing the echo as it returns, the bats can sense the location of objects. Echolocation works so well that bats can fly and find food in total darkness without hitting anything. They can also tell distance, size, texture, and speed of travel. Their huge outer ears help to gather this information more effectively than many other animals. This allows them to distinguish between prey and non-prey objects. If you were to stand in a room with flying bats, it is very unlikely that one would touch you. You are not a prey object!

In addition, bats have special cells in their ears that make them very sensitive to noise. They can hear the sounds made by their prey, such as faintly buzzing insects and croaking frogs. Some bats' hearing is so sharp that they can even detect the sound of a beetle walking on a leaf.

Benefits of Bats

Bats provide several useful benefits to humans. They eat huge numbers of insects, which provides natural pest control that helps farm crops, humans, and animals. Scientists estimate that bats save billions of dollars in reduced crop damage from insect pests every year. Also, as the primary predators of destructive night-flying insects like moths and beetles, bats help to keep our forests healthy.

field of wheat

The spread of fruit seeds is a natural benefit that comes from fruit-eating bats, as they eat the fruit and then deposit seeds in other areas through their waste. The seeds will then germinate and grow more of those plants. In the tropics, 95% of rainforest regrowth is due to seed dispersal from bats! Bats also help to pollinate plants in much the same way as bees and butterflies do by collecting pollen on their bodies when they eat.

Pollinator bat Mexican long-tongued bat

Bats are key pollinators for yummy foods such as mangos, avocados, bananas, dates, and cashews. In fact, over 300 species of fruit in tropical and desert climates depend on bats for pollination. In some areas of the world, bat excrement (known as guano) is gathered from caves and used as fertilizer for farms and gardens. Scientists study bats to further expand our understanding of flight, sound, and sonar. There are some areas of the world where bats are a huge tourist attraction, which helps local communities.

Bats have many potential uses in medicine and human health. Since the saliva of vampire bats contains a chemical that stops its victims' blood from clotting, scientists have used it to develop a medicine that helps patients who have had strokes or bleeding issues. Studying how bats use echolocation has helped scientists develop assistive devices for blind people. Research on bats has also led to advances in vaccines. In addition, about 80 medicines come from plants that rely on bats for their survival.

Bats can have some negative effects, as well. Like all mammals, bats can have rabies, which can be passed through their bite. This dangerous disease is especially concerning for herds of cattle or other livestock, but can also be passed to humans. Although most bats do not have rabies, it is important not to handle any bats you might find. Bat waste (guano) can become a problem when bats gather in buildings or public areas. Large colonies of bats roosting in warehouses or abandoned buildings can create a nuisance in city environments. However, scientists agree that bats' essential role in plant pollination, seed dispersal, and insect control makes up for the negative effects.

How Can You Help Bats

USFWS little brown bat
tri-colored bat with visible signs of WNS

Bats are essential to the health of natural ecosystems and to human economies as well. With all that bats do for us, you wouldn't want to live in a world without bats! But today, they are threatened from several sources, and bat numbers are declining across the globe. White-nose syndrome is a fungal disease that has caused the death of millions of hibernating North American bats. Habitat loss is a widespread problem for bats who depend on forests to roost and hunt. Wind turbines can pose risks to bats who may collide with them. In addition, some people fear and misunderstand the value of bats, and many bat colonies have been destroyed by humans.

Fortunately, there are things you and your family can do to help bats. You can avoid disturbing bats. You can share what you learn about bats to help other people learn how important they are. You can avoid the use of pesticides that can harm bats and reduce their food source. Remember, hungry bats provide natural bug control! Turning off outdoor lights and providing a dark nighttime environment can help improve conditions for bats. If you visit a cave, be sure to clean your clothing and shoes before entering so as not to spread disease.

Bat house

Building backyard habitats for bats has become a new conservation effort in many communities. Planting a garden helps attract pollinating insects that bats feed on. Bat houses, constructed in people's yards and natural areas, provide shelter for bats to roost. Providing bat houses also discourages bats from roosting in our houses, barns, or attics. Find out more about what makes a good bat house and how to create one that bats will love to make their home.

Top 10 Questions

September 2014

Thanks to Dr. Jesse Barber, Assistant Professor of Biology, Boise State University; and Rita Dixon, State Wildlife Action Plan Coordinator, Idaho Department of Fish and Game for the answers.

  1. What do bats eat?

    Bats eat a lot of different things, including blood, frogs, fish and birds. Most bats eat either fruit, some kind of plant material like nectar, or insects. In Idaho, our bats are insectivorous. This means they eat insects. (From Katherine at Pioneer School of the Arts in Boise)

  2. Why do bats hang upside down?

    Bats hang upside down because being up high keeps them safe from predators and it's a really good place for bats to take off from. Bats don't have very strong feet like birds, so hanging from the ceiling allows them to take flight easily. (From Avery at Dalton Elementary School in Dalton Gardens)

  3. How do bats fly?

    Bats fly because their wings are especially designed for flight. Their wing membranes have two layers that are tight. Flight for bats comes from lift, thrust and drag. So, the bat wing creates an air flow that allows the bat to go up and maintain their flight through air circulating around their wings. (From Katelan at Prospect Elementary School in Meridian)

  4. How many fingers do bats have?

    Bats have five fingers. In fact, the scientific name for bats is Chiroptera, which means hand wing. (From Cooper in Boise)

  5. How many species of bats are there?

    There are over 1,200 species of bats. This number continues to grow as we discover new species of bats. (From Jolie at Dalton Elementary School in Dalton Gardens)

  6. Where do bats live?

    Many bats live in large numbers in caves, but there are a lot of bats that live in trees. They can live under the bark in small groups or underneath giant leaves that they use as modified tents in the tropics. Some bats even live all by themselves at the very top of trees, hanging by one foot and wrapping themselves with their tail so they look like a pinecone. Bats live as far north as Alaska and as far south as Argentina. (From Dominic at Dalton Elementary School in Dalton Gardens)

  7. What is echolocation?

    Echolocation is how bats see in the dark. They scream out and listen for the returning echoes. They produce sounds from their larynx, just like people do, but their sound is ultrasonic, or high frequency. We typically can't hear these sounds with our human ears. (From Ashley at Lewis and Clark Middle School in Meridian)

  8. Why do bats like the dark?

    Bats are pretty much the ecological equivalent of birds, except they operate on the nighttime shift. Bats have vision but their vision is adapted to dim light. This, along with the fact that they use echolocation, is why they are active at night. (From Kensie at Cole Valley Christian School in Boise)

  9. Do bats have night vision?

    Bats can see to some extent in the dark. Bats' eyes are developed to illuminate things, so their eyes are a little different from our eyes. Our eyes are equipped to have higher resolution, and bats' eyes are equipped to have higher illumination in the night. Remember, there are 1,200 plus species of bats that make their living in all different ways. Those that use echolocation as their dominant sense often have very tiny eyes and don't use them as much. Other bats may not use echolocation, but instead they use the footstep sounds that the bugs make and also use their eyes for hunting. (From Ararea at Dalton Elementary School in Dalton Gardens)

  10. What are mega and micro bats?

    Chiroptera, or the order of bats, is divided into two suborders, mega and micro bats. Mega means large. These bats are much larger, often with a six-foot wingspan. Micro bats are much smaller, and their eyes are very different too. The mega bats use their vision for getting around and foraging. They typically don't echolocate. Micro bats, on the other hand, depend almost exclusively on echolocation. (From Dillon at Dalton Elementary School in Dalton Gardens)