Bram Stoker’s Dracula and its subsequent movie adaptations were a hit with horror fans—but
for bats, they were a PR disaster. The vampire story depicts its titular villain transforming
into a bat in between feasting on his human victims. The animals had been associated with
vampires since Europeans first found blood-drinking bats in the Americas around the 16th century,
but Stoker may be responsible for solidifying the animal's monstrous reputation in the English-speaking
world.
The perception that all bats are mini Draculas is obviously false. It’s true that vampire
bats do exist, but they make up a small portion of the larger bat population. Of the 1300+
bat species on earth, only three drink blood, and they live exclusively in Central and South
America. If you do come across a white-winged, hairy-legged, or common vampire bat in the
wild, there’s no need to break out the holy water. Vampire bats are mostly interested
in birds and livestock. On the rare occasions when they do feed on humans, they drink only
up to a tablespoon of blood, which means you wouldn’t necessarily know you were bitten
until you found the mark. And really, what are you doing with all that blood anyway,
let the little guy have a sip.
Hi, I’m Justin Dodd. Today we’re talking about some common misconceptions you may have
heard about bats. Let’s get started.
Even though vampire bats rely on blood for their food and water, calling them blood-sucking
would be inaccurate. Unlike some hematophagus—or blood-eating—creatures like mosquitoes,
vampire bats don’t suck blood directly from their prey. Instead, they create a small incision
near an artery with their teeth and lap up the blood that pools on the skin. That would
technically make bats blood-licking animals. For the record—looking down to see a bat
drinking my blood like a cat laps up milk from a saucer is still an experience I’d
like to avoid, thank you very much.
As I mentioned, the vast majority of bats aren’t looking to make humans their snack.
Most bats eat either fruit or insects, which is why they should be viewed as environmental
heroes instead of pests. Fruit bats help disperse seeds and maintain plant life cycles in tropical
ecosystems. Some bats drink nectar, which makes them pollinators in the same way that
bees are. Mexican long-nose bats often feed on agave flowers, for example, helping to
propagate the plant—the next time you enjoy a nice tequila, raise your shot glass to Leptonycteris
Nivalis. [I mean, everyone will probably make fun of you for being a dork, but you
can’t let that get in the way of a good time.]
Insectivorous bats benefit the environment in a different way. One bat can consume its
body weight in bugs in a single night. Many of these insects would otherwise pose a threat
to crops, and bats save the agriculture industry at least $3 billion per year. More bats in
your backyard also means fewer insects around to ruin your summer nights outdoors.
Even vampire bats have something to offer humanity. Their saliva contains the aptly
nicknamed protein Draculin which prevents clotting, thus encouraging blood to flow freely
from their preys’ wounds. Researchers have long been interested in this protein’s potential
to break up blood clots in humans. According to a study published in the journal Toxins,
vampire bats may even hold the key to a new treatment for high blood pressure. The venom
of the common vampire bat has been found to contain a special class of blood pressure-regulating
peptides, and it could possibly be used to treat hypertension, heart failure, and kidney
disease. Would you look at that, lil winged science boys.
So bats won’t drain your blood, and they’re pretty good for the environment, but many
people still duck and cover when they see one. That’s due to the misconception that
bats tend to get tangled in human hair. Fortunately for your updo, getting tangled in a head of
hair would be just as unpleasant for the bat as it would be for you. This idea may have
actually originated as a way to discourage young women from going out at night. Regardless
of whether it succeeded in keeping women at home, the myth has stuck around. Occasionally,
bats do appear to swoop down toward humans, but it isn’t hair they’re after. The carbon
dioxide you breathe out attracts insects, which in turn may attract a hungry bat. When
this happens, the bat is able to use its excellent navigation skills to avoid a collision with
your head.
And that brings us to our next misconception: Bats have poor eyesight. This is one of the
more prevalent myths surrounding bats, and it may come from the fact that many bats use
echolocation to hunt. When bats emit pulses through their mouth or nose, those sound waves
travel forward and bounce off objects in the vicinity. By listening to the echoes of their
calls, bats can approximate the size and shape of whatever's in front of them. If the object
producing the echo is roughly the size and shape of an insect, the bat has likely found
dinner. It then uses a rapid sequence of calls to locate its prey before diving in for the
kill.
Echolocation makes hunting at night a lot easier, but it isn’t the only way bats assess
their surroundings. Contrary to the phrase “blind as a bat,” bats have eyes that
are well-adapted to seeing in the dark. Some use vision as their primary tool for locating
food. Some bats’ eyes are actually sensitive enough to detect ultraviolet light, making
them one of the more impressive sets of peepers in the animal kingdom. Dang. I guess it makes
sense that Batman has night vision built into his cowl.
Bats spend a lot of time upside-down, and for good reason. The position allows them
to take off quickly when they need to. Compared to other flying animals like birds, bats are
heavy relative to their lift capacity. That means they have a hard time taking off from
the ground. Their solution is to kickstart flight by literally falling. Dropping from
an upside-down position gives them the air and momentum they need to achieve liftoff.
At least that’s the case with most bats. We know of six bat species that don’t sleep
hanging upside-down. Members of the Thyropteridae family in South America and the Myzopodidae
family in Madagascar prefer to get cozy in large, unfurled leaves like those of a banana
tree. When they crawl inside these tubes, they roost with their heads facing up. They
use small suction cups on their wrists and ankles to secure themselves to the plant’s
smooth interior. The young leaves mature and unfurl after a few days, and when they do,
the bats are forced to find a new botanical sleeping bag to call home.
When they aren't getting compared to vampires, bats are often called "rats with wings." Though
they *are* generally small and furry, though, bats aren't flying rodents. They belong to
the order Chiroptera, which comprises about a fifth of the world's mammal species. The
bats in this group are the only flying mammals on Earth. The only other living creatures
capable of flight are birds and insects. Some so-called flying animals like flying squirrels
technically get around by gliding, but bats are true flyers. They are also the fastest
mammals ever recorded. A study published in 2016 found that bats can soar through the
air at speeds reaching 100 MPH. That makes them faster than other mammals renowned for
their speed, like cheetahs. Suck it, Chester.
We've established that bats are not going to make you a member of the undead or dive-bomb
your hair, but they aren’t totally harmless. According to the CDC, in the United States
bats are the No.1 source of rabies in humans. That doesn’t mean that every bat you see
is infected, though. Bats account for only a third of the roughly 5000 animals that test
positive for rabies each year, and worldwide you are way more likely to get rabies from
a dog than any other animal.
Among bats tested for rabies, only 6 percent carried the virus. That rate could be even
lower in wild populations, as bats weak enough to be caught and brought to a lab are more
likely to be sick to begin with. And even though bats are the top spreader of rabies
here in the states, the chances of them giving you the disease are low. The U.S. records
just 1 to 3 cases of rabies per year.
It's possible that bats account for a disproportionate number of those rabies cases because many
people don't associate them with the disease. People may be more likely to worry about getting
infected from a dog or raccoon bite than an encounter with a bat. The illness is usually
fatal when left untreated, but it can also be prevented with a highly-effective vaccine
if it’s caught in time. The bottom line is that if you see a bat that looks like it
might be sick, stay away from it. And if you come in contact with a bat or find one in
your bedroom after sleeping there, see a doctor right away. Look, you’re not gonna get super powers
so don’t even bother. Bruce Wayne wasn’t bit by a rabid bat, he was simply born wealthy.
In general though, there’s really not much reason to worry about the bats eating bugs
in your backyard at night—they’re doing more good than harm.
Thanks for watching Misconceptions. If you have another misunderstood animal you’d
like us to cover, leave it in the comments, we are at your service. If there’s one thing
I love in this world... it’s Keanu Reeves, but if there are two things, the other is
definitely helping correct some age-old misconceptions. I’ll see you next time.