Frequently asked questions
What is the smallest bat in the world?
The Bumblebee Bat (Kitti’s Hog-nose Bat, Craseonycteris thonglongyai) is the world’s smallest bat and also the world’s smallest mammal (in length) measuring up to 29 – 33 mm (1.1 – 1.3 in) in length and 2 g (0.071 oz) in mass as a full grown adult. When full grown, these bats are shorter in length than an adult’s thumb and weigh less than two Skittles.
What is the largest bat in the world?
The Giant Golden-crowned Flying Fox (Acerodon jubatus) wins the title of the largest bat species in the world because it has the longest wingspan, up to 6 ft! It is among the heaviest of all bat species, with individuals weighing up to 1.40 kg (3.1 lb). The Indian Flying Fox (Pteropus medius) and Great Flying Fox (Pteropus neohibernicus) can weigh more than the Giant Golden-crowned Flying Fox. The Giant Golden-crowned Flying Fox can only be found in the Philippines eating fruit and leaves.
Are all bats vampire bats?
No! Of the 1,400+ species of bats in the world, only three are vampire bats that drink blood. These three species of vampire bats only live in the New World tropics (i.e., South America, Central America, Mexico).
What do bats eat?
One of the coolest things about bats is the diversity of diets that the 1,400+ species of bats have! Many bats eat insects and are very important for nocturnal pest control. There are also many species of bats that eat fruit, which are known as frugivores. Some bats are like the hummingbirds of the night, drinking nectar from plants and pollinating the flowers in the process. There are many other interesting bats with specialized diets, such as those that eat fish or frogs, or other small animals. Lastly, the three species of vampire bats only drink blood!
Where do bats live?
Bats live on every continent except for Antarctica! Yes, there are bats where you live. Since bats are nocturnal, many people don’t realize that they have bats living near them. While many bats live in caves, there are also many species that do not. Some species live in trees, while others can live in the cracks in rocks. Some of the most successful bat species are those that enjoy living in human-built structures, such as bridges.
Are bats blind?
No! All bats are able to see, but there is quite a bit of variation in eyesight from species to species. Some species have night vision, such as the large flying foxes, which have a tapetum lucidum. The tapetum lucidum is what causes the eye shine that we see in animals like cats and owls, allowing the animal to see in dimmer light. Some species of bats are able to see ultraviolet light, such as species that drink nectar and pollinate flowers. However, other bat species without night vision rely on their echolocation to navigate and hunt in the dark. While these species do not have very good vision in dark settings, they are still able to see, much like humans are able to see in the dark.
Do bats carry rabies?
Most bats do NOT have rabies. All mammals can contract and carry rabies. Bats are not asymptomatic carriers of rabies, however it is not always easy to see if a bat has rabies or not, especially since most people are not familiar with normal bat behavior. It is very important that you NEVER touch a wild animal, include a bat, with your bare hands. If you find a bat on the ground or out during the daytime, there is a higher chance that it is sick or injured. If you encounter a bat in a building or on the ground, we suggest contacting a local rehabber.
What do bats do in the winter?
Since bats are found on every continent, except for Antarctica, not all bats have to deal with cold conditions during the winter. Those bats that are found in temperate climates with seasonal changes can have different strategies for dealing with cold weather. Some bat species migrate to warmer climates during winter months, such as the Hoary Bat (Lasiurus cinerisus). Other species will hibernate during the winter, such as the Little Brown Bat (Myotis lucifugus). Both strategies involve amazing feats. During hibernation, bats will reduce their metabolic rate, heart rate, and respiratory rate to such low rates that they are able to reduce their body’s energy use by 98%. Migrating species will travel very long distances to avoid cold weather! Just like bird migrations, it is impressive how they are able to navigate over thousands of miles between their winter and summer homes.
Why do bats hang upside down?
Almost all species of bats hang upside down. When bats are relaxed, their feet are automatically in a clenched position, making it easy for them to grab on to a surface. Hanging upside down allows them to let go and quickly fall to gain momentum for flight. Unlike birds that have hollow bones, bats have solid bones like all other mammals, which is why they have more need for the extra momentum gained from falling. What is really interesting is why bat’s blood doesn’t all rush to their head while hanging upside down! There are valves in their veins AND arteries to keep blood flowing in the right direction, while most mammals only need valves in their veins.
How long do bats live?
Bats are very special in the animal kingdom because of how long they live for their size. The oldest known bat was a male Brant’s myotis (Myotis brandtii) who lived at least 41 years. There are at least 22 bat species documented living more than 20 years and six species that live more than 30 years. There is still a lot to learn about how bats age and how long they can live.
What are bat babies called?
Baby bats are called pups! Bat mothers give birth to their babies like all other mammals. What is incredible is the size of pups when they are born – pups can be born weighing up to one-third of their mother’s weight. Luckily, most bat mom’s only have one pup at a time.
Where is the largest colony of bats in the world?
Bracken Cave is the world’s largest bat colony! Located near San Antonio, Texas, USA, this is a summer maternity colony for up to 20 million Mexican Free-tailed Bats (Tadarida brasiliensis). In 1992, Bat Conservation International purchased the land where Bracken Cave is located to protect it from the increasing threat of urbanization.
What is the fastest bat in the world?
The Mexican Free-tailed Bat (Tadarida brasiliensis) is not only the fastest bat, but also the fastest mammal! While the cheetah is famous for its speed, sprinting at speeds up to 75 mph, the Mexican Free-tailed Bat has been recorded flying in short bursts at speeds up to 100 mph!
Do bats have predators?
While there are not many animals that are able to catch a bat flying at night, bats still have predators that they need to watch out for. Owls, hawks, and snakes eat bats. There are even Bat Hawks (Macheiramphus alcinus) in sub-Saharan Africa that specialize on eating bats. Bats do play an important role in the food web, which is why it is concerning that bats are hunted by humans. Never kill and eat a bat; humans are not meant to eat bats.
If I install a bat house, will the bats move into it AND leave my house?
ANSWER: Bat houses are excellent management tools that can provide displaced bats with a safe alternate roost away from structures where they are unwelcome. Bats are faithful to their homes, and very rarely voluntarily leave an active roost for a bat house.
Even the most well-planned and humanely-intentioned bat exclusion means habitat loss and displacement for bats. For that reason, when an exclusion is planned, BCI recommends installing one or more bat houses nearby, well in advance. Learn more by visiting our bat house page
How can I get bats to leave and not come back?
When bats roosting in a structure are unwelcome, exclusion is the only permanent solution. The objective should be to get all bats safely out of a building and to keep them out permanently. Although projects can vary in scale depending on structure type, species present and roost location, the process is the same regardless of the number of bats or how long they’ve been there. A complete description of the bat exclusion process can be found here.
What if I find a bat (or a colony) out in the open?
Bats are sometimes found alone or in large numbers roosting on the exterior of structures, or in open structures like parking garages. These are usually temporary stopovers, sometimes during fall and spring migration. Left alone, these bats will usually continue on their way within a few days or weeks.
What if you WANT bats in your attic?
Each year, BCI staff field hundreds of inquiries about excluding bats from buildings. Occasionally, however, we get a call from somebody wanting to increase the numbers of bats in their building! Often these are abandoned buildings used for interpretive purposes, structures housing endangered or threatened species, or buildings owned by people who simply realize that the benefits of bat residents can outweigh drawbacks. See our bat house page where we have re-posted the archive of Bat House Research Project newsletters we published during our 10-year research project, for ways to accommodate more bats, while minimizing problems from guano or noise.
How I can discourage bats from roosting on my porch?
Some species such as pallid bats (Antrozous pallidus) use open porches, patios, or garages as temporary night roosts for feeding or social activity. Bats are usually absent from these sites during the day, and insect parts or guano may be the only evidence that bats were roosting the night before. These night roosting bats can be discouraged by making their roosting area ‘less comfortable’ by adding clutter or making roosting surfaces difficult to hang on.
Bat Roosting Deterrents (To be employed only when bats are NOT present)
- Mylar Balloons floating near the roost
- Strips of mylar material or even tin foil tacked up at the roost so they move in the breeze
- Curling ribbon (long pieces, curled and tacked at the roost)
- Plastic taped over the roosting spot (to make it too slick for their feet to hold on and hang there)
- Bright lights and fans
These ideas are intended for night roosting bats (i.e., bats roosting under eaves of a roof or on a porch, etc., digesting the insects they have eaten), and the idea is for the bats to develop new habits. Day-roosting bats are usually in nooks, crannies, and crevices and must be properly excluded.
What if I find a bat in my patio umbrella?
Some bat species, including tri-colored bats, evening bats and southeastern myotis, find the crevice-like folds of a closed patio umbrella to be a perfect day or night roost. These are often transient solitary bats , but small maternity groups of Evening bats have been observed in early summer. If mothers and pups are present, they should be left undisturbed until pups are flying on their own. Then, if the bats are not welcome, the umbrella can be carefully opened after the bats leave at night and left partially open to discourage roosting.
Are bats dangerous?
Bats do not attack people, and reports that they do are usually related to incidents where bats fly near people in swimming pools as they swoop in for a drink, or near people outdoors in the summertime, when insects are abundant around us; bats DO attack insects! However, bats, along with several other mammal species, are a “rabies vector” species. That means that there will always be incidences of the rabies virus in bat populations. However, bats do not “carry” rabies. The vast majority of bats do not become rabid and there is no evidence of epidemic outbreaks in bat colonies. That is because when bats become infected with rabies, they die from the disease. Rabies can only be contracted if the virus enters the nervous system through a bite wound or mucous membranes (eyes, mouth or nasal passages). The virus is not spread through contact with blood, urine or droppings (guano), but through contact with saliva or central nervous system tissue. The virus is almost always contracted by way of a bite from a rabid animal.
What is an ‘undetected’ bat bite?
Many people believe that it is common to be bitten by a bat and not feel it. Though it is not impossible for that to happen under unusual circumstances, most professionals who handle bats on a regular basis will tell you that bat bites hurt. Bats have small, sharp teeth made for biting through insect parts and a bite from an insectivorous bat feels very much like a needle jab. However, because those teeth are small and sharp, a bat bite might not bleed and might not leave a very noticeable mark on human skin.
Is bat guano harmful to my family?
ANSWER: Histoplasmosis is a respiratory disease caused by a fungus that grows in soil enriched by animal droppings, including those from bats. Ninety percent of all reported cases in humans come from the Ohio and Mississippi River valleys and adjacent areas where warm, humid conditions favor fungal growth. The disease is rare or nonexistent in most of Canada and in the far northern and western United States. The majority of cases are asymptomatic or involve flu-like symptoms, though some individuals, primarily those who are immune-compromised, become seriously ill, especially if exposed to large quantities of spore-laden dust. To be safe, avoid breathing dust in areas where there are animal droppings; if you must clean an area of bat or bird droppings, wear a respirator that can guard against particles as small as two microns.
The U.S. Centers for Disease Control and Prevention provides information about Histoplasmosis here.