But Why: A Podcast for Curious Kids

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) at the University of Derby in the United Kingdom. Professor Vahed also takes on some of your pressing insect questions: 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  There are over 9,000 known species of crickets on the planet. These insects are best known for singing and hopping! Insects are divided into different orders depending on what kind they are. Crickets are in the order known as Orthoptera, which contains grasshoppers, locusts, crickets and bush crickets, and katydids. Crickets and grasshoppers are different! For one thing, most grasshoppers make noise by rubbing one of their legs against one of their wings. But most crickets make sound by rubbing their two forewings (their front wings) together. One wing is jagged, like a little row of teeth. And the other wing kind of scrapes up against it, making a sound. The number of teeth on the scraper, the speed of the rubbing and how frequently they make the chirps differ depending on the species. So there are lots of different cricket songs. Try an experiment: Get a comb and run your fingernail across it. See if you can make a sound. If you have more than one comb, or a comb with two differently sized/spaced teeth, see if they make different sounds. Does the size of the fingernail make a difference in the sound? Try giving your comb to an adult and find out! In most cricket species, the males chirp to attract a female. And they mostly sing at night to help avoid predators.  But Karim Vahed says some studies have shown that predators like domestic house cats follow the chirps of the crickets to find and eat them! Imagine a cricket the size of a hamster! A cricket so big it would cover the palm of your hand if you were holding it. The giant wētā [say it: WEH-tah] is that insect!  There are several species of giant wētās. They all live in New Zealand and most of them are protected because they’re quite rare. Insects are the most diverse group of animals on the planet. There are more than a million known species (about 80% of all known animals). But scientists estimate anywhere from 10 million to 80 million insect species have yet to be discovered!

That’s just one of the questions we answer in this week’s episode, which also includes instructions on how to easily make your own ice cream at home! We’ll also tackle the why and how of melting ice cream and why some flavors tend to melt faster than others! Our expert in this episode is ice cream entrepreneur Rabia Kamara, of Ruby Scoops in Richmond, Virginia. It's going to be sweet! Download our learning guides: PDF | Google Slide  | Transcript After listening, if you're ready to try making ice cream at home, here's Rabia's easy recipe. INGREDIENTS: 2 cups of heavy cream 1 14oz can of sweetened condensed milk Optional additional flavorings: a splash of vanilla pinch of salt And whatever else you might want to add! (Chocolate chips, cookie crumbles, etc.) INSTRUCTIONS: Use a hand mixer to beat the heavy cream until it is the consistency of whipped cream, with peaks that hold their shape. Fold any additional ingredients into the sweetened condensed milk and add the mixture to the heavy cream and fold them together using a spoon. Put into a freezer safe container. Let freeze for about 8 hours. Enjoy!

The Washington Mystics of the WNBA join us in this episode to answer all of your questions about the sport of basketball and what it’s like to be a professional athlete. How many basketballs does the team have? Why do balls spin when you bounce them? Who invented basketball? Why are basketballs orange with black lines? Why do men and women play on separate teams? How do injuries impact professional careers? And do you have to be tall to play hoops? Download our learning guides: PDF | Google Slide | Transcript Resources Basketball Games for Kids Learn More About the WNBA

For the past 50 years, visitors to the Smithsonian National Zoo in Washington, D.C. have been able to observe giant pandas. It’s one of the few places in the United States to see these black and white bears. For our latest episode we took a field trip to the zoo to visit the three pandas currently living there and answer panda questions with zookeeper Mariel Lally. We tackle: Why do animals live in the zoo? Why are pandas black and white? Do pandas hibernate? How can we save the pandas? And check out our social media pages for lots of pictures! Download our learning guides: PDF | Google Slide | Transcript Three pandas live at the National Zoo: adults Tian Tian and Mei Xiang and their cub, Xiao Qi Ji.  Zookeepers are never in the same space as the pandas. Even though they are herbivores, pandas are still wild animals with sharp claws and big teeth, so it’s important for people to stay safe. Researchers at the National Zoo have worked with colleagues in China on a breeding program for both captive and wild pandas. That research has helped pandas go from endangered to vulnerable. They’re still at risk of extinction, but doing better than they were just a few decades ago. Pandas eat 100 pounds of bamboo per day! The National Zoo cuts bamboo from sites around the D.C. area, including at some local private homes. Researchers aren’t sure why pandas are black and white, but the leading theory is that the white color provides camouflage in their snowy natural habitat and the black fur helps them blend in when they hide in shady bamboo forests. Panda cubs do have predators in the wild. Pandas do not hibernate, but they spend their time eating or sleeping. They have a period of deep sleep, similar to the torpor of reptiles. Keepers say they try not to wake sleeping pandas because they get very grumpy! (So the saying, “Never wake a sleeping bear” is especially true for pandas.) Zoo pandas get daily training to make their care easier. For example, they learn their names and they are taught to open their mouths and show a paw so they can more easily receive medical care. Zoos used to display animals primarily for human enjoyment. Now, most zoos focus on species conservation, research and educating the public about animal species.  Resources National Zoo’s Panadriffic Pack (games and coloring pages) Panda Cam

What is climate change? What is causing climate change? How do you cool down the earth? How is climate change affecting the oceans? Kids are hearing about climate change and they have lots of questions. In this episode we explain the science of climate change and look at how humans will adapt to a rapidly warming planet. We speak with Dr. Claudia Benitez-Nelson, oceanographer at the University of South Carolina and Dr. Jola Ajibade, a geographer at Portland State University. This certainly isn’t a comprehensive look at the issue, but it’s a good way to start a conversation about this issue for families and teachers. Download our learning guides: PDF | Google Slide | Transcript Climate is the long-term trend of temperatures and weather. You can think of the difference between climate and weather like a dog walking down a sidewalk: The dog might go from side to side of the sidewalk - that’s kind of like the weather - it varies. But the general direction of the dog is forward - that’s the climate. Since the 1800s we’ve had a lot of changes in technology that mean humans are burning a lot of fossil fuels like oil, gas and coal, to power engines, run our cars, heat our homes and create electricity. That puts a lot of greenhouse gasses and carbon dioxide into the atmosphere. The atmosphere is like a blanket around the earth. The increase in greenhouse gasses means that the blanket is getting thicker, making the earth warmer. Think of the earth like a human body: when a fever increases our body temperature by a few degrees, it can make you feel really sick (sometimes really hot, but other times with cold shivers). It’s the same thing for the earth! Even one or two degrees difference in average global temperature can make a big difference, including changing the amount of rainfall that a region gets or the overall temperature of the ocean, throwing our systems out of balance. Climate change can increase sea levels. As polar ice caps melt because of increasing temperature, the water levels rise, which can cause higher tides and more flooding. A good experiment you can do to visualize this is to grab a mixing bowl and turn a smaller bowl upside down inside of it (like an island). Pour some water and several ice cubes into the big bowl and see how high the water goes up the side of the smaller bowl. (You might need to weigh the smaller bowl down so it doesn’t float up.) As the ice melts, observe how the water level rises up the sides of the small bowl. Increased water temperatures are bad for coral reefs and other ocean animals. The best way to stop climate change is to stop burning fossil fuels. People will respond to climate change through coping mechanisms, including migration and relocation. The people most affected by climate change are the people least responsible for greenhouse gas emissions. If you’re concerned about global warming, find ways to consume fewer resources and to burn fewer fossil fuels. And lobby your government officials to make policies that benefit the environment and those most vulnerable to climate change. Resources NASA’s Climate Kids NASA’s Kids’ Guide to Climate Change National Geographic Kids Climate Change Explainer Take Action: Young Voices for the Planet Science Moms

Why do flowers bloom? How do flowers grow? Why are flowers different colors? Why do people find flowers beautiful? How are seeds made? Why do plants grow from seeds? Why do we put seeds in the garden? We’re answering your questions about seeds and flowers with garden writer Charlie Nardozzi and Hannes Dempewolf from The Crop Trust. Find more answers to plant questions in two of our older episodes: How Do Big Plants Grow From Such Small Seeds? and Are Seeds Alive?  Download our learning guides: PDF | Google Slide | Transcript New seeds are made through pollination, plant reproduction. Pollen makes its way to the ovary of a flower in various ways. Sometimes it is spread from one flower to another by a pollinator, like a bee or hummingbird. Some flowers are called “perfect”, meaning they can reproduce with their own pollen–not the pollen from another plant. But they still need a way for their own pollen to drop onto their egg. A gentle gust of wind, or the jostling of the plant by a gardener's hand can do the trick.  The flower will create the seed and then the flower structure will fade, leaving behind a seed. Sometimes it’s in a pod, sometimes it’s in a fruit or other structure to protect it.  Seeds are alive, but dormant. They contain all the nutrients needed to make a new plant. That seed will wait for the right conditions to germinate and create a new plant. Some seeds only need a little moisture to germinate, others need to be submerged in water. There are many different kinds of seeds and they have different necessary conditions. Flowers can be many different colors. They use those colors to attract pollinators. Those colors are created by pigments, natural colorings, in the plants. Some plants only flower once per year, others can bloom multiple times. Some plants flower in spring, others in summer, and some in fall. There is a lot of diversity in plants and the way they reproduce. That benefits all of us because if some plants aren’t thriving in certain conditions, other plants may do better.  Resources Seed sprouting experiment Window gardening for kids Webinar: Gardening with Kids

Why are some people right-handed and some are left-handed? And what’s up with some people being ambidextrous (equally good with both hands)? Why, in the past, did some people try to make left-handed people use their right hands? We talk with Chris McManus, professor and author of the book Right Hand, Left Hand: The Origins of Asymmetry in Brains, Bodies, Atoms, and Cultures. We’ll even find out how common left-handedness (or left-pawedness) is in other animals! Download our learning guides: PDF | Google Slide | Transcript Why do we prefer one hand over the other? McManus says it probably pays to specialize. It’s better to do something with one hand over and over and get really good at it, as opposed to doing it sometimes with one hand and sometimes with the other. For example, it takes years to develop your handwriting, so it would take twice as long to develop good handwriting with both hands! How do we pick which hand? We chose the hand that feels more normal to us, and then we practice with that hand. Try a simple experiment: bring your hands together quickly and entwine your fingers like you’re holding hands with yourself. Which thumb do you have on top? Now switch which thumb is on top. It probably feels a bit wrong. 90 percent of people use their right hand more. Our brain is asymmetrical (different on the right and left sides), and most of us use the left half of our brain to talk. Our heart is also on the left side of our body for most humans and vertebrates. There must be an advantage to being left-handed or we wouldn’t have left-handed people, but no one is sure exactly what that advantage is. What about people who say they’re ambidextrous? McManus believes there’s no such thing. He says people who say they’re ambidextrous are generally good at different things with each hand, but aren’t actually equally good at everything with both hands. McManus calls these people mixed-handers. Many animals also have handedness. But while right-handedness is dominant i people, animals tend to split down the middle. (So, for example, half of cats are right-handed, half are left-handed. Same goes for dogs and mice etc. in the 19th century, when people wrote with pens dipped in inkwells, writing with your left hand was messy business, as left hands would smear ink across the page. But as people have shifted to mostly typing, the hand you write with matters less. For every five left-handed boys, there are only four left-handed girls, and scientists have no idea why.

Why do pigs snort? And why do we call their snorts “oink” in English? We’re taking our exploration of animal noises in two directions today. First we’ll learn about why we use different words to describe animal noises, depending on what language we’re speaking. And then we’ll examine what animals are actually saying when they oink or tweet or moo! Our guests are linguist and author Arika Okrent and bioacoustic researcher Elodie Briefer, of the University of Copenhagen. Other questions we tackle in this episode: Do cows make different amounts of “moos” to say different words? Why do ducks make loud noises? Why do roosters cockadoodle-do in the morning? PLUS, so many kids sent us animal noises in different languages and we’ll hear them all! Download our learning guides: PDF | Google Slide | Transcript Bioacoustics is the study of sounds made in nature. Scientists like Elodie Briefer study how animals make sounds and what information we can find in those sounds. Scientists will record sounds and use computers to measure and analyze what they hear and use observational skills to help determine what the sounds might mean. Animals speak in emotion, not in words. Pigs have contact calls as well as positive and negative calls. Researchers have found that pigs will make longer calls when they are unhappy. Scientists and animal welfare advocates hope to use this information to eventually develop an app that farmers can use to improve animals’ lives on farms. With words like moo, oink and cockadoodle-do, we are giving a name to a sound. But we’re not just trying to mimic the sound. Most of us can make the sound of a pig snort but we need words like oink because we don’t want to stop using our language to make a pig snort in the middle of a conversation. Human voices are capable of millions of sounds but a language only uses a subset of those sounds. Our animal noise words will use the sounds available in our individual languages. Words that sound like the sound they are describing are called onomatopoeia. An animal has to have some cultural importance for a language to create a word for its call. That’s why we don’t have words in English for the noise a camel or a sloth would make. In Turkish there is no word for a pig call because that culture doesn’t keep pigs on farms.

We’re bringing back an episode from the archives, all about the moon: Why does the moon change shape? How much does it weigh? What color is it? Why does the Earth only have one moon? Why does it have holes? Where does it go when we can't see it? Why do we sometimes see it in the daytime? And why does the moon look like it's following you when you're in the car? Answers to your moon questions with John O'Meara, chief scientist at the W.M. Keck Observatory. Download our learning guides: PDF | Google Slide | Transcript | Coloring Page We can see the moon during the day for the same reason we see the moon at night. The surface of the moon is reflecting the sun's light into our eyes. But we don't see the moon all the time during the day, and that's because of where the moon might be in the sky. There are times where the moon is on the other side of the earth so we can’t see it. We see the moon in the sky when it’s in the right spot and it’s reflecting enough light to be brighter than the background of the sky. The moon is a satellite. A satellite is something that moves or rotates around a planet, the earth in this case. The moon is 239,000 miles away. That's far, but it's way closer than any of the other stars or planets you can see in the night sky. That's why the moon looks so big compared to other celestial objects even though the stars are actually much bigger. The moon weighs 100,000,000,000,000,000,000,000 pounds. That’s a lot! But it’s such a big number it’s hard to imagine how much that weighs. Instead, think about how much the moon weighs compared to the Earth. It turns out that the moon is about 1% percent the mass of the earth. That’s a lot! When you’re in a car and it feels like the moon is following you, what you’re actually seeing is an optical illusion. The moon is very far away, compared to anything else you see when you're driving — like the telephone poles that appear to fly past your car as you're going down a highway. But the moon is so far away that its size and shape in the sky doesn’t change, so it feels like the moon is following you.

The invasion of Ukraine has been the top story in the news for the last few weeks, and kids around the world are asking questions about what is happening and what it means for them. In this episode we ask Erin Hutchinson, Assistant Professor of Russian History at the University of Colorado Boulder, to help us understand the history behind this conflict. Adults: we don’t go into detail about what war looks like on the ground, but we acknowledge war is a scary topic. You may want to preview this episode ahead of time to make sure it's right for your kids. Download our learning guides: PDF | Google Slide | Transcript We have collected some resources for parents/caregivers about how to talk to kids about war and ways families can help.  How to talk to kids about war Meet the Helpers Common Sense Media News Sources for Kids from Common Sense Media NAMLE Parent’s Guide to Media Literacy Ways To Help Save the Children UNICEF Eurasia Foundation Donations for refugees in Moldova