JOAN CARTAN-HANSEN, HOST: Most people don't look at bats and think, "Well, there goes a species essential to our ecosystem."

But you know way, you should.

Bats are very important.

Let's find out why.

(music) >> SO, WHAT ARE WE GOING TO LEARN TODAY?

JOAN: BATS.

>> YOU MEAN BATS?

OR BATS?

OR BATS?

JOAN: NO, BATS.

BATS ARE MAMMALS.

THEY HAVE FURRY BODIES.

THEIR WINGS ARE REALLY WEBBED HANDS WITH THIN SKIN STRETCHED FROM THEIR LONG FINGERS TO THEIR BACK LEGS.

BATS ARE THE ONLY MAMMALS THAT FLY.

A FEW OTHER MAMMALS CAN GLIDE, BUT BATS ARE TRUE FLAPPING FLIERS.

THE FASTEST BAT CAN FLY AT MORE THEN 30 MILES PER HOUR.

ONE OF THE BIGGEST BATS IS THE GOLDEN-CAPPED FRUIT BAT.

IT'S A FRUIT-EATING BAT WITH A WINGSPAN OF MORE THAN 5 FEET.

THE SMALLEST BAT, AND, INDEED, THE WORLD'S SMALLEST MAMMAL, IS THE HOG-NOSED OR BUMBLEBEE BAT.

IT WEIGHTS LESS THAN 2 GRAMS AND IS THE SIZE OF A BUMBLEBEE.

WORLDWIDE, THERE ARE MORE THAN 1200 DIFFERENT KINDS OF BATS.

BATS SLEEP DURING THE DAY AND FEED AT NIGHT.

MOST BATS FIND THEIR FOOD USING ECHOLOCATION.

THEY MAKE RAPID HIGH-FREQUENCY SOUNDS.

THESE SOUND WAVES BOUNCE OFF THEIR PREY AND TRAVEL BACK TO THE BATS' EARS.

THE BATS HEAR THE ECHO AND FIND THEIR DINNER.

SOME BATS EAT THINGS LIKE FRUIT OR FROGS OR SMALL BIRDS, BUT MOST BATS EAT INSECTS.

LITTLE BROWN BATS CAN CATCH 250 MOSQUITO-SIZE INSECTS IN 15 MINUTES.

A BAT EATS ABOUT HALF ITS OWN WEIGHT IN INSECTS EACH NIGHT.

IF YOU WEIGHED 100 POUNDS, THAT WOULD BE LIKE EATING 50 ONE-POUND PIZZAS EVERY DAY.

MANY BATS LIVE IN COLONIES.

THEIR HOMES ARE CALLED "ROOSTS".

JUST LIKE YOU AND ME, BATS NEED SHELTER FROM THE WEATHER, PROTECTION FROM ENEMIES, AND A PLACE TO REST.

SOME LIVE IN CAVES OR TREES, BUT OTHERS LIVE UNDER BRIDGES OR INSIDE OLD BUILDINGS.

PUPS, OR BABY BATS, ARE BORN IN THE SUMMER.

IN THE WINTER, SOME BATS MIGRATE TO WARMER CLIMATES.

OTHERS HIBERNATE.

SCIENTISTS STUDY BATS BECAUSE A LOT OF THESE SMALL FLYING MAMMALS ARE THREATENED.

MANY BATS ARE IN TROUBLE BECAUSE PEOPLE DISTURB THEM WHILE THEY'RE ROOSTING OR REMOVE THEM FROM THEIR HOMES.

SO, IF YOU FIND A BAT, IT'S IMPORTANT TO LEAVE IT ALONE.

BATS ARE ALSO IN TROUBLE FROM A NEW DISEASE CALLED "WHITE-NOSE SYNDROME."

SO, IF YOU GO INTO A CAVE, CHANGE YOUR CLOTHES AND CLEAN YOUR SHOES AND GEAR SO YOU DON'T SPREAD DISEASE FROM ONE CAVE TO ANOTHER.

>> BUT BATS CAN BE SCARY.

JOAN: WELL, MOVIES AND TV SHOWS HAVEN'T BEEN VERY NICE TO BATS.

BUT IN CHINA, BATS ARE SYMBOLS OF GOOD LUCK.

BATS ARE A REALLY IMPORTANT PART OF OUR ECOSYSTEM.

THEY EAT LOTS OF INSECTS AND HELP POLLINATE CROPS AND SPREAD SEEDS.

HUMANS NEED BATS, AND, SADLY, ABOUT 25% OF THE WORLD'S BATS ARE THREATENED WITH EXTINCTION, SO WE NEED TO DO MORE TO PROTECT THESE AMAZING ANIMALS.

If you want to learn more about bats, check out the Science Trek website.

You'll find it at ScienceTrek.org (MUSIC) ANNOUNCER: Presentation of Science Trek on Idaho Public Television is made possible through the generous support of the Laura Moore Cunningham Foundation, committed to fulfilling the Moore and Bettis family legacy of building the great state of Idaho.

By the Idaho National Laboratory, mentoring talent and finding solutions for energy and security challenges, by The Friends of Idaho Public Television and by the Corporation for Public Broadcasting.