That's a question a lot of people have, honestly. But a kid named Rosie was bold enough to ask us to investigate why. So, in the latest episode, we dig in on why cockroaches get such a bad rap and why you might want to reconsider if you're not a fan.

Only two percent of the world's cockroaches are considered pests. Those are the ones that can live in houses and potentially make us sick. But the vast majority of cockroaches don't bother humans at all! Some, like the social cockroach species known as termites, work to decompose organic material and are hugely important to our environment. So where do people learn negative attitudes toward insects? We dig deep into insects with Jessica Ware, an entomologist and curator at the American Museum of Natural History. She's also the host of the PBS digital series Insectarium. Answers to your questions about cockroaches, termites, dragonflies, praying mantises and more!

Download our learning guides: PDF | Google Slide | Transcript

Why do lizards have scales? Why are reptiles cold-blooded? Why do lizards have long tongues? How do lizards grow their tails back? Are crocodiles dinosaurs? What's the difference between an alligator and a crocodile? Why do crocodile eyes look like they have mirrors in the back? How do crocodiles chomp? Why do crocodile teeth stay sharp? Why are crocodiles green? Why do crocodiles swim? Answers to all of your crocodile and alligator questions with Venetia Briggs-Gonzalez, one of the researchers known as the Croc Docs at the University of Florida.

Download our learning guides: PDF | Google Slide | Transcript

Why do people dance? Where did ballet come from? How do you make pointe shoes for ballet? How does practice make you better at things? But Why visited Dance Theatre of Harlem to get answers to these questions with company artists Derek Brockington and Lindsey Donnell.

Download our learning guides: PDF  | Google Slide | Transcript

A solar eclipse is coming to North America on April 8, 2024. The moon will line up perfectly between the Earth and the sun, blocking out the sun's light and casting a shadow that will pass over parts of Mexico, the United States and Canada. People in the path of totality will experience a few minutes of darkness during the day as the moon perfectly covers the sun. Those not in the path of totality in those countries will still experience a partial solar eclipse. In this episode, we're answering questions about the eclipse and talking about how to keep your eyes safe if you're watching it! We speak with Bridgewater State University solar physicist Martina Arndt, Fairbanks Museum planetarium director Mark Breen and Thomas A. Hockey, author of America's First Eclipse Chasers.

Download our learning guides: PDF | Google Slide | Transcript

Why are there Burmese pythons and chameleons in the Florida Everglades? We might not know how those animals arrived but they are causing damage to the natural ecosystem. An invasive species out competes native plants and animals in an ecosystem. So how does this happen? But Why travels to the Everglades to learn more about how and why species end up in places they shouldn't. Plus, why are we sometimes told to kill invasive insects like the spotted lanternfly?

Download our learning guides: PDF | Google Slide Transcript

How is snow made and what's it made out of?  Why is it white and sparkly?  Why do snowflakes look different? Can snowstorms have thunder? Why do some places, like mountains, get more snow than others? Answers to all of your questions about snow, with Seth Linden, who works for the National Center for Atmospheric Research in Boulder, Colorado. Plus we hear what it's like to live at the top of Mount Washington, famous for its extreme weather, from Alexandra Branton, a meteorologist who works at the observatory at the top of the mountain, even during the frigid winter.

Download our learning guides: PDF | Google Slides | Transcript

How do glasses work? Why do some people need glasses and other people don't? Why do we have different eye colors? We answer your questions about glasses and eyes in the second of two episodes with Dr. Sujata Singh, a pediatric ophthalmologist at the University of Vermont Medical Center. And we hear from Maggie, a kid with low vision, about what it's like to need glasses. 

Download our learning guides: PDF | Google Slide | Transcript

What shape are our eyes? What are they made of? How do they work? What's the point of having two eyes if we only see one image? Why do we blink? What's the point of tears and why are they salty? We answer your questions about eyes in the first of two episodes with Dr. Sujata Singh, a pediatric ophthalmologist at the University of Vermont Medical Center.

Download our learning guides: PDF | Google Slide | Transcript

We've collaborated with our podcast friends at What If World to bring you the first (and only) episode of…But Why If World! In this episode we jointly answer some “what if” questions. What if cereal could talk to us? What if dinosaurs didn't lay eggs? What if the world started spinning backwards? Take a listen to this curious collaboration.

Download transcript

For our last episode of each year, we often like to ask our listeners around the world to send us something fun. This year, we wanted you to tell us what makes you happy and you had a lot to share on that topic! Our listeners find happiness in spending time with friends, family, and pets and in doing activities they love: playing with friends, toys, arts and crafts, participating in sports, watching movies, and riding bikes. Two people say the special sandwiches their adults make them are what bring them happiness. And some kids told us learning new skills is especially exciting for them. In this episode: a happiness bonanza with all the responses we got. Plus we talk with a happiness expert: Gretchen Rubin. She's the author of the Happiness Project and host of a podcast called Happier with Gretchen Rubin. 

Download our learning guides: PDF | Google Slide

Almost half the people in the world speak at least two languages. And, it turns out, that includes a lot of But Why listeners! In this episode we talk about what it's like to speak multiple languages and kids from around the world share phrases in many different languages so we can all learn something new! Plus, linguist and professor Anna Babel answers questions we've gotten about languages, including: What does it mean to be bilingual? Why do some people speak two or three languages? How many languages can someone learn?

Download our learning guides: PDF | Google Slide | Transcript

How are electric guitars made? How are guitar strings made? And how, exactly, do guitars work? We're answering questions about electric guitars with local luthier (guitarmaker) Lea in Burlington, Vermont. Creston gave us a tour of his studio–including his custom glitter room, to help us understand what goes into making an electric guitar.

Download our learning guides: PDF | Google Slide

For the past 50 years, visitors to the Smithsonian National Zoo in Washington, D.C. were able to see giant pandas. But recently, China asked for those pandas back. (Technically, all pandas in the United States are considered “on loan” from China.) With pandas in the news, we're bringing back the episode from our 2022 field trip to the zoo. Zookeeper Mariel Lally answered all of your panda questions. Among the questions we tackled: Why do animals live in the zoo? Why are pandas black and white? Do pandas hibernate? How can we save the pandas? Check out our social media pages for lots of pictures!

Download our learning guides: PDF | Google Slide | Transcript

Why do we celebrate birthdays? Why do we have birthday cakes? Why do we blow out candles on our birthdays? Why are our birthdays on the same date but a different day of the week each year? This episode has answers to all of your birthday questions - plus we hear about unique birthday traditions sent in by our listeners! 

Download our learning guides: PDF | Google Slide | Transcript

Why do some people like haunted houses and scary movies? What is fear? Why do humans have fear! Why do we get goosebumps, blink a lot and scream when we're scared? Why are some of us afraid of what's in our closet or under the bed at night?

We look at fear, and the fun side of fear with Marc Andersen, who co-directs the Recreational Fear Lab at Aarhus University in Denmark. He studied fear and play and how they intersect. Turns out, moderate and controlled fear can actually have benefits to our mental health!

Download our learning guide: PDF | Google Slide | Transcript

How is meat made in a lab? That's what 10-year-old Nate in New Jersey wants to know! Scientists have figured out how to grow meat in laboratories. Some hope lab-grown meat will be able to help address issues like global food insecurity, agricultural pollution and animal cruelty. But 5-year-old Lorenzo in California wants to know why people have to eat meat anyway? But Why visits scientist Rachael Floreani of the Engineered Biomaterials Research Laboratory at the University of Vermont to learn more about how and why lab-grown meat is being developed.

Download our learning guides: PDF | Google Slide | Transcript

Younger people have lots of questions about older people, like: Why do we age? Why do people get gray or white hair? Why do older people have wrinkles? Why do older people have veins that stick up? Why are older people more tired? Why do some people get shorter as they get older? Dr. Suvi Neukam, a geriatrician at Oregon Health and Sciences University, answers kids' questions about aging in this episode.

Download our learning guide: PDF | Google Slide | Transcript

Why do birds fly? How do raptors soar? Why do some birds fly in the shape of a V? Why can't some birds, like penguins, emus and ostriches fly? Why do hummingbirds fly so fast? We answer all of your questions about birds and flight with help from Anna Morris of the Vermont Institute of Natural Science and Bridget Butler, the Bird Diva. And we get a preview of our new education series But Why: Adventures! Northeast Nature. Educators: learn more about But Why: Adventures! Northeast Nature and sign up for free access to the series!

Download our learning guides: Video |  PDF | Transcript

We're thinking about bears! Actually one specific type of bear: sun bears! Have you heard about this type of bear? They're the smallest of the world's bears, about half the size of a black bear. They live throughout southeast Asia and have a yellow or white crescent-shaped marking on their chests. We learn about sun bears with Wong Siew Te, a scientist and researcher who runs the Bornean Sun Bear Conservation Centre in Malaysia. Also in this episode: Do bears live in caves? Why do they climb trees? Why do bears hibernate in winter? Naturalist Mary Holland answers questions about hibernation. And we are treated to A Bear Song by Key Wilde and Mr. Clarke!

Download our learning guides: PDF | Google Slide | Transcript

It's all about bikes in this episode of But Why? How come bicycles stay up when you're riding, but fall over once you stop? We turn to Andy Ruina, professor of engineering at Cornell University, for the scientific answer. We also learn how a bike chain works and Olympic mountain biker Lea Davison tells how to get started when riding.

Download our learning guides: PDF | Google Slide | Transcript

11-year-old Alaska (from Colorado) wants to know: why do some kids love reading while others don't? We know there's a lot of debate lately about the best ways to teach kids how to read. But in this episode we leave the pedagogy to adults and let kids share with one another why they love to read and their best tips for kids like them, who may be struggling to learn (and love) to read. Plus, guest Fumiko Hoeft, medical doctor and professor at the University of Connecticut and at the University of California San Francisco, lifts the lid on our brains to explain what's happening inside us when we learn to read. Dr. Hoeft runs a brain imaging research program and a lab called BrainLENS.

Download our learning guides: PDF | Google Slide | Transcript

How are crickets so loud? Why do they chirp at night? How are they different from grasshoppers? We're talking crickets today with Karim Vahed, a cricket and katydid expert and entomologist (bug scientist) in England who works with BugLife, the Invertebrate Conservation Trust. In this episode, Professor Vahed takes on some of pressing general insect questions as well: Do insects have bones? What do baby bugs like to do? Do insects drink water? Why are bugs so important?

Download our learning guides: PDF | Google Slide | Transcript

Why is it that some people have allergies when others don't, even if they're in the same family? How do allergies work? Can you be allergic to water? Why are some people allergic to cats and dogs? Can you grow out of your allergies? We're joined by pediatrician and allergy researcher Dr. Ruchi Gupta to answer the dozens of questions kids have sent us on this topic. Plus we learn about promising treatments being developed to help relieve allergy suffering.

Download our learning guides: PDF | Google Slide | Transcript.

What are eels? And why are some eels electric? We head to Poughkeepsie, New York to learn about eels with Chris Bowser, Hudson River estuary educator with the New York Department of Environmental Conservation. Plus we learn about electric eels. Electric eels have captured the imagination of many people, but they're not actually considered eels by the scientific community. They're a type of knife fish, more closely related to catfish and carp. But they are electric! So we'll tackle why they're electric and how they create electricity. David de Santana, of the Smithsonian Museum of Natural History, tells us what it's like to study electric eels in the Amazon. 

Download our learning guides: PDF | Google Slides

Why do people spend so much time on social media? But Why answers kids' questions about social media and screen time and we learn about how to be a good citizen online with Devorah Heitner, author of Screenwise: Helping Kids Thrive (and Survive) in Their Digital World and Growing Up In Public: Coming of Age in a Digital World, coming in September.

Download our learning guides: PDF | Google Slide | Transcript

Why do wolves howl at the moon? Do wolves have different howls? How were wolves domesticated into dogs? How do wolves run fast for so long? What kind of habitats do wolves prefer? Why are people scared of wolves? Do they eat people? How do we protect them? But Why visits the Wolf Conservation Center in South Salem, New York, where education director Regan Downey answers kid questions about these apex predators.

Download our learning guides: PDF | Google Slide | Transcript 

Do bears ever live in cities? Why do so many crows gather together on winter nights? How many raccoons are there in cities? What's the deal with so many maple trees in Vermont? Why are flowers different colors? How are snakes born with venom? Why do some foxes turn white in the winter and others don't? Where is a good place to observe wildlife? How do urban wild places support wildlife in cities? Naturalist Teage O'Connor answers questions from Burlington classrooms in this special live episode of But Why. 

Download our learning guide: PDF | Google Slide | Transcript | Scavenger Hunt

Why are babies small and grownups big? Why are babies so helpless, instead of little versions of adults? Do babies know they're babies? How do babies grow? How do babies learn to talk?

Kids have been sending us lots of questions about babies! This week we're learning more about the development of the human brain with Celeste Kidd, professor of psychology and primary investigator at the Kidd Lab at the University of California Berkeley.

Download our learning guides: PDF | Google Slides | Transcript

One of the things that makes blood so special is we can share it with other people! Scientists and doctors have figured out safe ways to take the blood from one person and put it into the body of a different person who needs it. That's called a transfusion. Why would someone need more blood? Doctors use blood transfusions to help people who have been in accidents and to treat people with certain kinds of cancer, sickle cell disease and other conditions. But if you've never heard about this before, it can sound kind of strange and alarming to think about giving away something that is so necessary to your life! In our second blood-related episode we'll tag along with Jane as she donates some of her own blood.

Download our learning guides: PDF | Google Slide | Transcript

Why do people have blood, what is it, and what does it do? How do our bodies make new blood? Is it red or blue? Why does blood taste like metal? And why do we have different blood types? Our listeners have a lot of questions about blood. We learn about blood with UVM Medical Center and Larner College of Medicine pathologist Dr. Sarah Harm. 

Download our learning guides: PDF | Google Slide | Transcript

How do water slides work and how are they built? Why do you have to be a certain age or height to go down a water slide? Where does the water in water parks come from? And which is easier to design and build: a water slide or a roller coaster? First we did a little research of our own at Jay Peak Pump House Water Park. (And by “research” we mean “going down the water slides.”) And to teach us more about what's actually happening when you take your thrill ride, we talked with water slide engineers Songyi Moon and Kelly Sall at WhiteWater West.

Download our learning guides: PDF | Google Slide | Transcript

In this episode: part two of parentisms- you know, the things adults like to say that may or may not be true. So many of these sayings have to do with food: Eating carrots will improve your vision.  Drinking coffee will make you shorter. Don't swallow watermelon seeds or they'll grow in your stomach. We do a little fact checking on this generational eating advice with Dr. Nusheen Ameenuddin of the Mayo Clinic. And we explore a few other sayings you sent us, like why do parents always say, “Next time” when they really mean “No”? And what the heck does it mean to keep your eyes peeled?

Download our learning guides: PDF | Google Slide | Transcript

We wanted to hear about the conventional wisdom, parenting myths, and downright folksy falsehoods adults pass down to kids, and boy did we get a big response! We heard from over 100 of you about everything from “Don't swallow gum because it will stay in your stomach forever” to “Slouching will crush your organs” to “If you don't take a shower after swimming in the pool, your hair will turn green.” In this episode (the first of two), with the help of pediatrician Nusheen Ameenuddin of the Mayo Clinic, we put these “parentisms” to the test! Find out if there's any truth to the idea that TV will turn your brain to mush, you'll catch a cold if you go out with wet hair, and it's dangerous to take a shower during a thunderstorm. Oh, and by the way, this is our 200th episode!!!

Download our learning guides: PDF | Google Slide | Transcript

In addition to having faces that look like a smiley emoticon, axolotls are as fascinating to scientific researchers as they are to kids because of their amazing ability to regenerate parts of their bodies, including their brains! In this episode we answer kids' questions about these curious salamanders with Dr. Randal Voss, a professor at the University of Kentucky. That lab alone has thousands of axolotls, but these creatures are critically endangered in the wild, where they live exclusively in the depleted and polluted waterways of Mexico City's Lake Xochimilco. Questions we tackle in this episode: How do axolotls regrow parts of their brains? What did axolotls evolve from? Can axolotls survive out of water?

Download our learning guides: PDF | Google Slide | Transcript

What do bison, moose, Gila monsters, parrots and snails have in common? Well….nothing, except they all appear in this episode! We're rounding up some of the animal questions you've sent us lately. Why do bison walk slow but run fast? What's the thing hanging down from the neck of a moose? Why do Gila monsters bite? How do parrots talk? Why do snails have slime? Answers from the Fort Worth Nature Center & Refuge, San Diego Zoo Wildlife Alliance and One Earth Conservation.

Download our learning guides: PDF | Google Slide | Transcript

As we close out 2022, Jane and Melody look back at some of their favorite episodes of 2002. Why do we have friends? Why are some people left-handed? Why do pigs oink? And why is Russia invading Ukraine? Did you have a favorite episode? Let us know! Kids can record a video talking about a favorite episode and then tag us on social media or send an email to questions@butwhykids.org.

Episode Transcript

Full episodes

Why do we have friends?

Why are some people left-handed?

Why do pigs oink?

Why is Russia invading Ukraine? 

How do big cargo ships and ferries float, even though they are so heavy? Why do boats float but stones sink? How do paddles make boats move? What's inside those enormous container ships? We learn about the physics of floating with Fahad Mahmood, professor of physics at the University of Illinois Urbana-Champaign. If you do any of the activities we mention in the episode, send us your videos!

Download our learning guides: PDF | Google Slide | Transcript

Why do armadillos have shells? How do they roll into balls? Why are sloths so slow? Can sloths actually move fast? How do they defend against predators? Why do they have such long nails? We learn about two unique looking animals in this episode: sloths and armadillos. These mammals are part of an ancient superorder called Xenarthra and share a common ancestor. To get answers to kid questions about armadillos we took a field trip to Texas to talk with Michael Perez at the Forth Worth Nature Center and Refuge. And to learn about sloths, we interviewed Sam Trull of the Sloth Institute in Costa Rica.

Download our learning guides: PDF | Google Slide | Transcript

Emoji are those little images you can send in text messages to friends and family. Nine-year-old Leila in New Jersey wants to know how they were invented. So in this episode we find out with Jane Solomon, editor at Emojipedia and Paul Galloway of the Museum of Modern Art in New York. We learn what the first emoji looked like, way back in the dark ages of the 1990s and we explore how emoji may be a new trend, but communicating through pictures is a very old tradition. Plus, are emoji…art? Give this episode a 👂to find out!

Download our learning guides: PDF | Google Slide | Transcript

But Why has answers to your dinosaur questions! When did the dinosaurs live? How many species of dinosaurs were alive in the Cretaceous period? How do dinosaurs get their names (and why are they hard to say)? Why are dinosaurs extinct? We visit Dinosaur Valley State Park in Texas to see some actual dinosaur evidence: tracks left by two types of dinosaur 113 million years ago.

Download our learning guides: PDF | Google Slide | Transcript

• Dinosaur Valley State Park in Glen Rose, Texas has several sites where dinosaur footprints have been well-preserved. Though some of the tracks were actually chiseled out and sold before the park got state recognition and protection.

• In the summer of 2022, drought in this part of Texas caused riverbeds to dry out, revealing new tracks that hadn't been seen before. These discoveries made news around the world!

• The rock in the area is limestone. And the tracks are largely in what are now riverbeds. But In the time of the dinosaurs, 113 million years ago, the landscape looked very different. The sea covered much of the land, and the spots where the tracks are were the seashore, full of sticky wet mud. The dinosaurs walked through the mud and left footprints, which were then covered over by silt and other sediment. As the mud got compressed and eventually turned into limestone, the tracks were preserved.

• The landscape changed over the millennia. As the sea receded and rivers curved through the landscape, the flowing water eroded the limestone, eventually revealing these tracks that had been covered for millions of years.

• Some of the tracks at Dinosaur Valley State Park are about the size of a large dinner plate look like classic dinosaur prints, with three long toes and claw marks. Those are from a dinosaur called Acrocanthosaurus.

• Acrocanthosaurus was shaped like a Tyrannosaurus Rex. It walked on two legs and had a large ridge down its back. It was a carnivore and likely the apex predator in its North American environment.

• The other dinosaur whose tracks have been found at this state park is Sauroposeidon. These tracks are much bigger and rounder, more like an elephant track. They're so big a kid could sit inside one as if it was a bathtub!

• Sauroposeidon was a huge dinosaur. It walked on all fours and had a long tail and a very long neck. It weighed as much as 44 tons and was as tall as a 6-story building. In fact, it may have been the tallest animal that has ever lived!

• Sauroposeidon was an herbivore, and may even have been hunted by Acrocanthosaurus. The two dinosaurs lived at the same time and made the visible tracks at the park within hours or days of each other.

• The biggest dinosaurs lived in the Cretaceous period,145 million to 65 million years ago. It's estimated there were as many as a thousand different dinosaur species in that time period, but only a few hundred have so far been named.

• Most paleontologists believe most dinosaurs died out more than 65 million years ago when an asteroid hit planet Earth.The asteroid itself didn't kill all the dinosaurs all at once, though it was big enough to cause a lot of devastation. It also kicked up a huge cloud of dust and debris that essentially blocked sunlight from reaching the earth. This caused plants to die. Without plants, large herbivores didn't have enough to eat. When the herbivores died, the carnivores had nothing to eat and they died, too.

If you want to see the dinosaur tracks, check out our videos on YouTube.