Ask a Scientist
|Dr. Nancy Simmons is a biologist from the American Museum of
On April 4, 2006, students and teachers interviewed Dr.
Nancy Simmons, a biologist at the American Museum of Natural History.
To learn about how bats "see" with sound, who keeps bats as
pets, and what bat skin feels like, read the transcript below.
What's your favorite kind of bat?
My favorite bats are New World Leaf Nosed Bats. They're really pretty
and they do all sorts of different things. Some of them eat insects,
some eat fruit, and some visit flowers to get nectar and pollen even
the vampire bats are members of this group. They are also pretty easy
to catch, which is good when you're a bat biologist.
Where do you go to study bats?
I go to South America and Central America. There are a couple reasons
for this. One is the tropics have the greatest diversity of bats because
there's more food available all year round. And the other reason is
I've done research there in the past and I know the animals well. From
a scientific perspective it's important not to get spread too thin and
do too many things, so I like to keep my fieldwork in the same geographic
What did you think of bats when you were a kid?
I've always thought bats were cool. They were more mysterious to me
as a kid than they are now, but I've always liked them. I never actually
saw or handled a bat up close until I was in college.
What's an exciting discovery you've made about bats?
The most exciting thing I've learned is how some fossil bats are related
to living bats no one knew this before. I used features of the fossil
bats skeletons to put them in the bat family tree and show how they
were related. What's really neat is some of the fossils that are very
old don't come out on the bottom of the tree; they actually represent
lineages that come out further up the tree. That means the diversification
of the bat families happened a long, long time ago.
Are there female bats and male bats?
Yes. They have some of the same characteristics that male and female
people do. Sometimes you catch female bats with their babies or pregnant.
When they're pregnant, they're huge because female bats give birth to
one large baby at a time like humans do. This is different than many
other mammals like cats and dogs and mice that have litters of many,
I read that bats use echolocation so they know where to fly.
What exactly does that mean?
Echolocation means using sound to identify obstacles rather than using
vision. Bats make very high frequency calls and then they listen for
the returning echoes. Their brains process the returning sounds in terms
of how fast the echo comes back, the frequency of the returning echo,
and they use this information to "see" what's around them
in their environment. Some bats are so good at this that they can detect
tiny flying insects and calculate their speed and direction. The bats
use this information to catch and eat their prey.
Have you been bitten by a bat or almost bitten by a bat?
If so where and what did you do?
I have been bitten many, many, many times by bats. When you catch a
bat in a net, it reacts like any other scared animal and it bites. I'm
pretty good at handling bats without getting bitten, but sometimes I
do mess up. Usually I get bit on the fingers. What's really interesting
is that in all the many times I've been bitten by a bat, I've never
gotten an infection. When I accidentally cut myself with a knife doing
fieldwork, I seem to always get an infection. When I do get bitten by
a bat, I just treat it like a regular cut.
What's a surprising fact about bats that most people don't
All bats can see, and many of them can have quite good vision including
bats that use sonar.
Have you ever spent a lot of time with one bat? Why and what
was it like?
I can't say that I have. Usually we collect data from one bat and release
it as fast as possible to avoid causing it any more discomfort or stress
Does anyone keep a bat as a pet?
Some people do. Mostly this happens in the Old World Tropics where people
have Flying Foxes as pets. In some villages people get Flying Foxes
as babies and raise them. There are people in the U.S. who keep bats
to educate people, but they're not really pets.
How many bat species are there? Are any endangered?
There are 1,116 species of bats that we know about, and there are probably
many more that are yet unknown to scientists. Many of these species
are endangered, mostly due to loss of habitat.
What is one mystery about bats that you hope to solve?
I hope to eventually build a complete family tree of all bat species
including fossil bats. I think within 10 years we'll have it.
Have you ever discovered a new species of bat? What was that
I have discovered and named new species of bats. It's very exciting.
At first it's confusing because you expect to be able to identify what
you've caught and it's confusing when you have a bat that doesn't fit
into any preconceived notions of what species there are. Then, when
you realize that you are seeing something really, truly new for the
first time, it's really exciting.
Why do you think bats have such a bad reputation?
Because people don't understand them. They are small; they are nocturnal;
they move fast; and they don't stand still for you to examine and look
at them so people don't understand them and make up stories about
What other animals do you find interesting and why?
I like lots of different kinds of animals. One of the animals is called
a katydid, which is a big insect related to grasshoppers. They're fascinating.
They're very diverse and they sing wonderful songs at night. I've seen
many interesting katydids when I'm out catching bats.
What other subjects are you interested in besides bats any
I spend time with my kids. I also do tae kwon do and I run for fun.
What's a typical day like for you at the museum?
For every month that I spend in the field, I take at least another year
to write up the results, so I spend a lot of time at my computer writing
papers on my research findings. I have a microscope in my office and
I also spend a lot of time looking at bat skulls and teeth and studying
Do vampire bats suck human blood?
There are three species of vampire bats. Two of those species prefer
to feed on birds. However, the Common Vampire Bat prefers mammal blood
and it's not picky. So yes, they do feed on people sometimes, but they
don't suck blood. They use their very sharp front teeth to make little,
tiny cuts and then lick the cuts with their tongue to get the blood.
The most common place for a person to get bitten is on their hands and
feet that might stick out from a hammock while that person sleeps. Hammocks
are common in the tropics. The chances of being bitten by a vampire
bat in the United States are almost zero.
Are all bat species related back to one common bat ancestor?
Yes. All bats evolved from a single ancestor.
Are bats smart?
Yes. Bats are smart, they live a long time and they can learn a lot
about where they live. They remember where their food resources are
and where their roost sites are, and if things change within their home
range, they can adapt as long as things don't change too much.
Do bats ever fight with each other?
I wouldn't say that bats fight with each other. They compete with each
other for resources, but they don't really fight.
Why do some bats eat one thing, like frogs, and others eat
other things, like blood?
Different bat species have evolved to take advantage of the different
resource in their environment. Some bats have evolved to only use one
food source but most bats use multiple kinds of food sources. What I
mean by that is they don't rely on just one thing. For example, an insect-eating
bat will eat many different kinds of insects. Some bats are real generalists
they will eat insects, fruit, feed from flowers, all kinds of things
depending on what's readily available at the time.
What does bat skin feel like?
Bat skin feels like your skin. It's warm and stretchy so touching
the wing of a bat feels like touching the skin on your arm. Of course,
most of the bat is covered with fur, and it's very soft fur like on
What is the average age that bats can live?
Nobody knows. We know that some bats live a very long time for such
small animals. There are cases where a captive bat has lived 30 years.
Considering that a mouse of a similar body size can live two years at
the most, it's very impressive how long bats seem to live. Scientists
who study aging are interested in bats because of this.
Do bats have bones? If so, what's their skeleton like?
Bats have bones. They have many of the same bones that a person does,
but their bones are different shapes. The wing of a bat is supported
by very long finger bones. So, it's the same bones as a person has but
very elongated and that's what supports the wing membrane.
What kind of school did you go to in order to become a bat
To become a biologist, you need to go to college and usually to graduate
school. I went to college in California, Pomona College, and I went
to graduate school at the University of California, Berkeley, and that's
where I got my PhD. But there are many different universities where
you can do research on bats. What's important when choosing where to
go is what kind of classes you can take and what kind of research is
being done by the professors because you learn most from your advisors.
What kinds of subjects should kids study if they want to be
The most important thing is math because much of what we do in science
is based on mathematics. It's also important to take science classes.
It can be helpful to study foreign languages because if you want to
do work outside the United States, it's good to know the local language.
It's also good to take courses in writing because that's how scientists
communicate with one another.
Who is your favorite scientist and why?
I really like Ed Wilson who spent his whole life studying ants. He generalized
what he learned from ants to apply his ideas and help understand the
evolution of life.
What do you think of superheroes like Batman and Batwoman?
I have a picture of Batwoman on my wall. One of my students gave it
to me. I think they're fun, but they don't have much to do with bats.
How fast do bats grow?
Bats grow very fast in their first few weeks of life and reach adult
size within a couple months of birth.
How can bats eat so much without getting fat?
They exercise a lot. Being a small mammal requires a great deal of energy
to power your metabolism. And for bats, they need the added energy to
fly, which takes up a lot. So, the problem for bats isn't getting fat
but finding enough food to eat.
How can you observe bats when they're only out at night?
To observe bats you need to be active when they are. In the summertime
in the U.S., bats come out before dark and you can see them in the twilight.
But for a bat biologist, you need to work at night if you want to learn
How many bats can live together at one time?
In a single place in the rainforests of South America, I have personally
captured 78 species all living in the same area. And that was undoubtedly
not all of the species living there. We think that there are over 100
species living together in some areas of the New World Tropics. In terms
of individuals, there are caves with as many as 30 million bats living
together in them.
Do you think bats might live near me, but I've just never seen
If you live in the U.S., bats live near you. You just haven't seen them.
Is it possible to get rabies if you get bitten by a vampire
Yes. It's also possible to get rabies from a bat that's not a vampire
bat, but it's a rare disease even among bats. The vast majority of living
bats don't have it.
What would you say to kids who are afraid of bats?
Learn about them! They aren't scary. They're beautiful and fascinating.
What kind of studying or exploring do you think it's important
for all kids to do?
It's really important for kids to get outside and explore the natural
world. Look at everything and ask questions.
My cousin says there are bats in his attic. What should he
The best thing to do is to leave them alone unless they're causing trouble.
If they are causing problems, he should call an exterminator.
Were you interested in science when you were a kid?
I've always been interested in science, particularly natural history
and biology. I was always the kid with a jar full of tadpoles and a
snake in my pocket.
About how many species of bats are there in Florida?
There are about 10 species of bats in Florida. If you want to know more
about them, go to the library and get a field guide for North American
What's the best thing about being a biologist?
My job is to study animals and nature. What better job can there be
How do bats care for their young?
Female bats look after their babies until they're old enough to find
food on their own. When they're little, the mother leaves them in the
roost while she goes out to find food. Bats are mammals, so the mother
makes milk that the baby feeds on when it's very small. When the youngster
gets big enough, the baby will follow the mother to learn how to find
food. The relationship ends only when the mom is ready to have another
There are so many different kinds of bats. Are they more diverse
than other animals?
Bats are more diverse than any other kind of mammal. Only rodents are
more diverse. But bats are not very diverse at all when compared to
insects or fish. There are many, many more insect and fish species than
bat species or other mammals.
Do you think you'll ever learn all you want to know about bats?
No, because every time you learn something new, it raises more questions.
We are just beginning to learn about how bats live and how they evolved.