Are whales communicating with their clicks and songs?

TYLER: You're listening to Brains On!, where we're serious about being curious.

CREW: Brains On!, is supported in part by a grant from the National Science Foundation.

[RAIN SPLATTERING]

MARC SANCHEZ: Ah, rainy Sunday afternoon, the perfect time for some cozy relaxation. Cushy recliner, check; crocheted blanket, a-check; mug of tea with lemon and honey, oh, check. Now, to put on some relaxing sounds. [SIGHS]

[DOOR OPENS, CLOSES]

SANDEN TOTTEN: Marc, my dude! It's a rainy Sunday.

MARC SANCHEZ: Yes, I know, perfect for relaxing.

SANDEN TOTTEN: So what are you listening to?

MARC SANCHEZ: The ideal soundtrack for relaxation, whale songs.

SANDEN TOTTEN: Like a wailing guitar solo, doo, doo, doo, doo, doo, wawn, wawn, wawn.

MARC SANCHEZ: No, not a wailing guitar. Ooh, a song made by a whale, you know, a big, beautiful ocean mammal.

SANDEN TOTTEN: Oh, yeah, yeah. Right, right, right, right, right, yeah.

MARC SANCHEZ: You want to try sitting down and relaxing? It's pretty nice if you give it a try.

SANDEN TOTTEN: OK, sure. Why not? Relaxing. Relaxing. This isn't too bad. But Marc, I'm not sure the whale song is relaxing enough. You know what I mean? It's relaxing. But is it max relaxing? Is it relax maxing?

MARC SANCHEZ: If I let you switch the music to something more relaxing, would you stop talking and just chill out?

SANDEN TOTTEN: Definitely. Harvey, play the Sanden whale song.

[MUSIC PLAYING]

SANDEN TOTTEN: Yeah. This is the stuff.

MARC SANCHEZ: Sanden, make it stop.

SANDEN TOTTEN: What? I can't hear you. I'm too busy relaxing.

[ANNOYING MUSIC]

[THEME MUSIC]

MOLLY BLOOM: You're listening to Brains On! from APM Studios. I'm Molly Bloom, and my co-host today is Tyler from Freeport, Maine. Hi, Tyler.

TYLER: Hi, Molly.

MOLLY BLOOM: Today's episode is about some of the biggest, most breathtaking animals in the ocean, whales. Tyler, you wrote to us a few years ago with an awesome question about whales, right?

TYLER: Yeah. I wanted to know if each individual whale sings a different song.

MOLLY BLOOM: Very cool. Yes, so we know that whales sing, like how birds sing. But you want to know if each whale has their own unique song or if a group of whales all sings the same song. So what made you think of this question?

TYLER: Well, a couple of years ago, I was going on a whale watch in Massachusetts, and that was really fun. I saw all sorts of different whales. It's where a lot of people go out on a big ship and watch for whales.

MOLLY BLOOM: Oh, that's so cool.

TYLER: We saw a whole pod of fin whales.

MOLLY BLOOM: Wow.

TYLER: They're the second biggest.

MOLLY BLOOM: That's amazing. Where did you do your whale-watching?

TYLER: I did my whale-watching near Plymouth, Massachusetts.

MOLLY BLOOM: Oh, very cool. What was it like seeing a whale in real life?

TYLER: It was incredible. A fin whale swam right under the boat and looked at us.

MOLLY BLOOM: Whoa. So, Tyler, what is your favorite thing about whales?

TYLER: Probably, the size of their hearts.

MOLLY BLOOM: Whoa. How big is their heart?

TYLER: A blue whale's heart is the size of a car.

MOLLY BLOOM: Whoa. That's so cool. Yeah, sometimes it's hard to remember how big whales are, but then you realize their heart is the size of a car. And it reminds you how giant they are. So I'm wondering, can I hear your best whale impression?

TYLER: Oh gosh.

MOLLY BLOOM: I can do mine first if you want.

TYLER: Very well.

MOLLY BLOOM: Whoo, hoo, hoo, hoo, hoo. That's mine.

TYLER: That sounds like the whale from Finding Nemo.

MOLLY BLOOM: True. It's probably the most I've heard of whales is from Finding Nemo, or at the beginning of the song "Baby Beluga" by Raffi. At the beginning they go, vrrr. I've heard that a lot of times, too. Back to the question at hand, can I hear your best whale impression?

TYLER: Oooh, oohm.

MOLLY BLOOM: Very nice. Yeah, whales are incredible. But, Tyler, before we answer your question, we need to cover some whale basics.

TYLER: There are lots of different kinds of whales, but all of them are grouped into two categories-- baleen whales and toothed whales.

MOLLY BLOOM: Baleen whales include humpbacks and blue whales. They have rows and rows of thick bristles inside their mouths, like a comb. These are called baleen plates, and they're made of something called keratin, the same stuff our fingernails are made out of.

TYLER: Baleen whales use these thick, bristly plates like a strainer. They use their mouth to suck in ocean water full of tiny animals like Krill. The Krill gets trapped in the baleen, and then the whales eat them.

MOLLY BLOOM: Toothed whales, like their name suggests, have teeth. They use those chompers to catch their meals. There are all different kinds of toothed whales, like belugas, sperm whales, dolphins, and orcas.

TYLER: Baleen and toothed whales don't just have different ways of catching their food. They also make different whale sounds.

ANNA GOLDFIELD: Did somebody say whale sounds?

MOLLY BLOOM: Its Brains On! producer Anna Goldfield. And yes, we were just talking about whale sounds.

ANNA GOLDFIELD: Oh, wow, what a coincidence? I'm on my way to audition for a whale song choir.

TYLER: A whale choir, like a bunch of humans who sing whale songs?

ANNA GOLDFIELD: Oh, no, no, no. I sing with humans all the time, like Molly, the Hello song we sing whenever we see each other.

Hello, hello, hello, hello. It's nice to see your face. Hey!

MOLLY BLOOM: Gosh, I love singing that.

ANNA GOLDFIELD: Ah, I know. So fun. So anyway, I have plenty of human singing in my life already, so I'm auditioning to join a choir of actual baleen whales. They're humpbacks, and they're amazing. Check out this recording of their last performance.

[WHALE SOUNDS]

TYLER: Oh, wow.

ANNA GOLDFIELD: I'm pretty sure it's a whale choir, and I'm pretty sure they'll be holding auditions soon.

MOLLY BLOOM: That might be a leap, but yeah, let's go with it.

ANNA GOLDFIELD: So to help get ready for my audition, I've been looking into how whales make their songs, and it's so wild, turns out baleen whales have voice boxes.

MOLLY BLOOM: Cool. Humans have those, too.

TYLER: Yeah, the voice box is a long, hollow tube in our throat that helps us breathe and make sounds.

MOLLY BLOOM: Exactly. And inside of that tube, humans have something called vocal cords. If you touch your neck and say something, you'll feel your vocal cords vibrating, like this. [THROAT VIBRATION]

ANNA GOLDFIELD: Wow.

MOLLY BLOOM: You can really feel those vibrations. So is that how whales make sounds, too, with their voice boxes?

ANNA GOLDFIELD: Yeah, kind of. Baleen whales do have voice boxes like us, but they don't have vocal cords like we do. So how they make sounds has actually been a mystery for a while. But scientists think they might have finally figured it out.

MOLLY BLOOM: Oh, I love it when a mystery starts to unravel.

ANNA GOLDFIELD: Yeah. So scientists studied voice boxes taken from three different baleen whales in a laboratory. These whale voice boxes are much bigger than ours. They're about 2-feet long.

TYLER: Whoa. That's a big voice box.

ANNA GOLDFIELD: Yeah, sure is. And when they looked inside the whales' voice boxes, scientists found that they had this special muscle. It's shaped kind of like the letter "U." And that U-shaped muscle sits right up against a cushion of fat inside the whales throat.

TYLER: A U-shaped muscle in the throat next to fat. How does it work?

ANNA GOLDFIELD: Scientists think that whales force air from their lungs past this U-shaped muscle inside their voice box, and that makes the cushion of fat start to vibrate, which makes sounds, like these.

[WHALE SOUNDS]

MOLLY BLOOM: Wow, that's pretty amazing.

ANNA GOLDFIELD: I know. And fun fact, that recording actually came from a hugely popular album of humpback songs produced by a whale biologist. The album helped people connect with whales and inspired them to protect these majestic sea creatures.

TYLER: Oh, yeah, there's a whole episode on the history podcast Forever Ago about that. It's a really cool story.

ANNA GOLDFIELD: Sure is.

TYLER: That reminds me, I read that only male baleen whales can sing. True or nah?

ANNA GOLDFIELD: That's true. Scientists don't know why only the males sing, but they think it has to do with finding other whales to mate or with marking their territory. Oh, and get this, they can sing underwater while holding their breath.

MOLLY BLOOM: Anna, that seems like it might be kind of hard for a human to do. How are you going to audition for this whale choir?

ANNA GOLDFIELD: Ha, ha. Minor details, Molly. Maybe there's some kind of underwater whale song adapter I can make for my scuba suit, or maybe the choir just needs a percussionist. Nah, I'll figure it out on the way to the audition.

TYLER: Thanks for telling us all about whale songs, Anna.

MOLLY BLOOM: Bye, Anna. Good luck with the whale choir audition.

ANNA GOLDFIELD: Thanks, you two. Bye.

MOLLY BLOOM: We're going to talk more about baleen whale songs and hear how toothed whales make sounds. But first, it's time for the--

CREW: SSSSSH. Mystery sound.

MOLLY BLOOM: Are you ready for the mystery sound, Tyler?

TYLER: I am.

MOLLY BLOOM: Here it is.

[MYSTERY SOUND PLAYING]

What do you think?

TYLER: Well, the first part of sounds almost like someone eating chips with this fan blowing. The second part, he might have dropped something or someone.

MOLLY BLOOM: Very good ears. Let's hear it again. I have no idea what this is, either, so let's-- I need to hear it again.

[MYSTERY SOUND PLAYING]

What do you think now?

TYLER: Now I'm thinking it's maybe some one snapping something for cooking.

MOLLY BLOOM: Oh. What do you think it could be?

TYLER: I don't know, but something related to cooking. And then they drop maybe the thing they were using to stir or something.

MOLLY BLOOM: Oh. Nice. I like that.

TYLER: Oh, wait. It might be a nutcracker, actually--

MOLLY BLOOM: I love that guess.

TYLER: --like cracking nuts. And then they put down the nutcracker.

MOLLY BLOOM: Yeah. So when you crack a nut, you're getting the shell off, and so you can eat what's inside.

TYLER: Yeah.

MOLLY BLOOM: Fascinating. We're going to hear it again, get another chance to guess, and hear the answer at the end of the show. So stick around.

[MUSIC PLAYING]

MOLLY BLOOM: We are working on an episode about how paper is made. Paper is all around us. There are pizza boxes, toilet paper, books, wrapping paper. We use it to pay people, wipe up messes, share ideas, and so much more.

And we want to see your paper creations. What have you made out of paper, origami sculptures, paper planes, collages? Tyler, what's something cool that you have made out of paper?

TYLER: About a year ago, I made these paper dragons by stapling and taping, and then I used some pencils. I still have them.

MOLLY BLOOM: That's really cool. How did you learn to make them?

TYLER: I don't know. I just someday thought I was bored. So then I was like, Ooh, what if I made a paper toothless? Then I did it, and then I made other stuff.

MOLLY BLOOM: That's so cool. Well, listeners, we want you to take a picture of your paper creations and send them to us at brainson.org/contact. While you're there, you can also send us your mystery sounds and questions.

TYLER: Like this one.

CREW: My question is, how many times does our heart beat a day?

MOLLY BLOOM: You can find answers to questions like these on the Moment Of Um podcast, a short dose of facts and fun every weekday. Find Moment Of Um and more at brainson.org.

TYLER: So keep listening.

ANNA GOLDFIELD: Brains On Universe is a family of podcasts for kids and their adults. Since you're a fan of Brains On!, we know you'll love the other shows in our universe. Come on, let's explore.

[SONIC BOOM]

CREW: Brains On! I'm their biggest fan. I also love Smash Boom Best, a fun debate podcast for kids and families. Listen, I will play you Smash Boom Best. You will love.

MARC SANCHEZ: To refresh your memory, The Ugly Duckling goes like this. A bunch of duck eggs hatch and the cute little ducklings go quack, quack, quack.

[DUCKS QUACKING]

Mother duck is super happy with her eggs when crack, the last one explodes and out comes this--

CREW: Zorp, where did the signal go? Must find Smash Boom Best now.

ANNA GOLDFIELD: Listen to Smash Boom Best wherever you get your podcasts.

CREW: Ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, Brains On!

TYLER: You're listening to Brains On! I'm Tyler.

MOLLY BLOOM: And I'm Molly. Today, we're talking all about whale songs. So far, we've learned that there are two main types of whales, baleen and toothed whales, and they make different sounds.

TYLER: Baleen whales make sounds with a special U-shaped muscle inside their voice box. That muscle helps them make all sorts of sounds. And some of them can even sing.

MOLLY BLOOM: We'll get to toothed whales in a minute. But first, let's answer your question, Tyler. Does every whale have its own unique song? And the answer is, they do not. If you're a baleen whale, swimming in the ocean, you wouldn't hear something like this.

- (SINGING) I'm Tommy, the humpback whale

This is my super special only me song

Which no one else sings, only me

MOLLY BLOOM: That doesn't happen. But a group of whales, called a pod, can all learn to sing the same song, like this.

- (SINGING) We're the humpbacks of the North Atlantic

We love to swim and splash and play

TYLER: Got it. So each individual whale doesn't have its own special song, but a group of male whales can learn to sing the same songs.

MOLLY BLOOM: Exactly. And when whales share a song with other members of their pod group, scientists can figure out who is part of each whale pod. Another cool thing about whale songs is that they can pass from pod to pod.

So when male whales feed close to each other in the ocean, they can pick up new phrases or learn entirely new songs from each other. We know this because scientists have tracked whale songs across oceans, meaning that they're passed between groups.

TYLER: Almost like a giant game of whale telephone.

MOLLY BLOOM: Exactly. Whale communication is complicated and amazing, and we're still trying to figure out what whales are saying to each other. We asked you to imagine what whales would want to tell us if they could talk to humans.

TYLER: And your responses were over-whale-mingly good.

SCHEELE: Hi, my name is Scheele, and I come from the Kingdom of Tonga. A lot of humpback whales come here to breed. I think if whales could talk to us, they'd ask us why we put so much rubbish in the ocean.

TOMAS: Hey, do you like fish and chips up there?

DILLON: I am aware, and I want to say, please save our Earth and protect our oceans, please.

PETRA: Hi, I'm Petra Reiss from Hollywood, Maryland. And this is what I think whales would say if they could talk. Stop using my poop as an ice cream flavor. It is not delicious. You should make human-flavored ice cream, then give it to me. Nom nom.

WINNIE: My name is Winnie. And I think if blue whales could talk, then they would tell us to stop polluting the ocean because the largest trash dumpsite in the world is the Pacific Ocean.

LENIX: If whales could say something to humans, they will say, I love you.

MOLLY BLOOM: Thanks to Scheele, Tomas, Dillon, Petra, Winnie, and Lenix for those responses. Tyler, what do you think whales would want to tell us if they could talk to humans?

TYLER: I think they would tell us about life under the sea. It would be pretty cool.

MOLLY BLOOM: That would be pretty cool.

TYLER: We could almost exchange information.

MOLLY BLOOM: I would love that.

TYLER: Also, I think they would tell us what their food tastes like.

MOLLY BLOOM: Oh. What do you think it would taste like?

TYLER: Pretty bland and giant squid I read in a book if we tried that. Someone once tasted them, and it tasted like urine because of a chemical.

MOLLY BLOOM: That doesn't sound that good.

TYLER: Yeah.

MOLLY BLOOM: I wonder how they would feel about our food if they tried it. They'd be like, wow, this tastes gross.

TYLER: Maybe.

MOLLY BLOOM: It's all an acquired taste.

CREW: Brains On!

MOLLY BLOOM: Baleen whales use special muscles in their throats to produce complicated songs.

TYLER: These whales don't have individual songs, but some types of baleen whales sing songs that can pass from one pod to another, eventually spreading across entire oceans.

MOLLY BLOOM: So far, we've only been talking about baleen whales, like humpbacks and blue whales. But the other kind of whale, toothed whales, also make sounds, and they sound like this.

[CLICKING SOUNDS]

TYLER: Those clicks come from a sperm whale living in the Caribbean ocean.

MOLLY BLOOM: Shane Gero is trying to figure out what those clicks mean.

SHANE GERO: I'm a scientist in residence at Ottawa's Carleton University. I'm the biology lead for Project CETI and the founder of the Dominica Sperm Whale Project.

MOLLY BLOOM: Shane and his team have recorded lots and lots of sperm whale clicks.

TYLER: And he says the way sperm whales make this noise is amazing. It starts with their nose.

SHANE GERO: Sperm whales have one of the coolest noses on the planet. For the big males, it can be one third of their body. And this is an animal that's the size bigger than a school bus that might take you to school.

And if you've ever blown up a balloon and pulled the mouth of the balloon tight, and it kind of makes a farty sound, it's making that farty sound because the two sides of the balloon are slapping together. And that's basically what sperm whales are doing in their nose.

They're filling a balloon and passing it between two pieces of skin that slap together and that makes the click sound. And then it travels through this big organ that's filled with oil in their head and gets amplified and directionalysed. It's one of the most powerful sounds made by any animal.

MOLLY BLOOM: Adult male sperm whales don't live in pods. They swim the ocean on their own. But female and young sperm whales travel in families-- grandmas, moms, and kids living their lives together.

TYLER: And since these whale families stay together, Shane and his team have gotten to know the ones that live around Dominica really well.

MOLLY BLOOM: Dominica is a small island country in the eastern part of the Caribbean Sea.

SHANE GERO: So we've been listening to the same families of whales for the last 20 years. And one of the big challenges now is to connect that to what they're doing and who they're doing it with when they make those sounds.

So if you only ever recorded English in a dentist's office, you'd think the word "cavity" is critically important to English-speaking society. But really it's because you're only recording dentists and kids in the dentist's office.

And so we need to record whales across all of the amazing things that they do to understand what sounds they make when they dive and what sounds they make when they're caring for a baby and what sounds they make when they're alone or together.

Because once you have the who's saying it and what they're saying, you can start asking the fascinating question of why. Like, what is so important to these whales that they want to make sounds with each other?

MOLLY BLOOM: It turns out that sound is incredibly important for these whales to survive.

TYLER: They sometimes spend an hour at a time deep in the ocean where there is no light at all.

SHANE GERO: So most of their life is in dark. And as a result, they're live in a world of sound. They use sound to see through the darkness in the same way we might use a flashlight to see through the dark, like bats see in the night sky. They make loud clicks that are very directional.

[CLICK SOUNDS]

They mostly are pointing those clicks straight ahead of them, and then they listen for the echo as it bounces off things. So they use sound to find food. They use sound to swim around in the deep ocean without bumping into things, and they use sound to communicate and stay in touch with each other so that they can always stay with their family because for them, family is critical to their survival.

For them, the most important isn't the ability to see. It's the ability to hear. And that's why things like our presence in the ocean, where we have lots of ships or lots of sonar sounds or looking for oil creates a lot of noise-- that creates something that we call ocean noise pollution. And that's really a concern for the whales because it makes it like living in a rock concert.

MOLLY BLOOM: When you're at a rock concert, [ROCK MUSIC] you have to talk like this.

TYLER: What did you say?

MOLLY BLOOM: I said-- wait. Can we turn the music off? Ooh, thank you. If it's hard for us to talk with loud noises happening, imagine how it is for whales. Humans are making lots of noise in the oceans, from boats and drills and whatnot. And that's making the ocean more like a rock concert.

TYLER: And that's not great for the animals that live there.

MOLLY BLOOM: Shane is just starting to figure out what sperm whale's clicks mean. But one thing we do know is that these animals are very smart.

SHANE GERO: And their brains are big mammalian brains, like ours. It's clear that this is a brain that's evolved, that's come into being for the sake of complicated thought. It's just really hard to study. But when you spend a huge amount of time in the company of individual whales that you know as individuals, you see things that science isn't yet good enough to quantify.

Like there's this amazing whale named Can Opener. And when we first started doing our science-- good scientists do things over and over and over and over. And so when we see a whale, we get behind it. We wait while it's at the surface. It lifts its tail. In that quintessential moment, we take a picture of its tail because that's how we identify them.

And then it disappears. And we go up to the footprint of water, the circle sort of where the whale just was. And we collect skin and feces, and we make recordings. And she figured that out. And so she would fake dives and wait underwater for the boat to come up to where she just was, and then she would blow out all her air and come to the surface.

But amazingly, she would roll her eye out of the water and look at the people on the boat. She didn't use her echolocation. She didn't use her sound vision to look at the hull of the boat underwater. She rolled her eye out of the water to look at the people who are now giddy and dancing around the boat because a whale is looking at them.

And to me, that shows that she saw something new in her environment. She realized it did a repeating pattern. She predicted the future by saying, I'll wait here and the boat will come, and then she rolled her eye out of the water, acknowledging that the complicated, fun thing were the little things on the big thing that's floating on her side of the surface.

And to me, it means that we can do better science by assuming that these animals are smart, that they think, that they care and have emotions about one another.

MOLLY BLOOM: Well, Tyler, does that change how you think about whales?

TYLER: It does. It changes it a lot. I knew whales were intelligent, but not this. And I didn't know that sperm whales lived in families. It's pretty cool.

MOLLY BLOOM: It is. It's very amazing. If you want to see photos of the whales that Shane has gotten to through his research, like Can Opener, the sperm whale, head to our website brainson.org or click on the link in the Show Notes. There are two types of whales in the world-- toothed whales and baleen whales. They both communicate using sound but in very different ways.

TYLER: Baleen whales sing songs using a U-shaped muscle in their voice box.

MOLLY BLOOM: Male baleen whales sing complex, patterned songs, and scientists are still discovering exactly why they're singing and what they're saying.

TYLER: But the coolest part about baleen whale songs is that they can change over time and are passed from whale to whale throughout our oceans.

MOLLY BLOOM: Toothed whales make clicking sounds. And sperm whales, a kind of toothed whale, have a complicated language made of clicks that scientists are just beginning to decode.

TYLER: That's it for this episode of Brains On!

MOLLY BLOOM: This episode was written by--

CHARLOTTE TRAVER: Charlotte Traver.

MOLLY BLOOM: --and me, Molly Bloom. Our editors are--

SANDEN TOTTEN: Sanden Totten.

MOLLY BLOOM: --and Shahla Farzan. Fact-checking by--

JESS MILLER: Jess Miller.

MOLLY BLOOM: We had engineering help from Colby Kelch and Derek Ramirez with sound design by--

RACHEL BREES: Rachel Brees.

MOLLY BLOOM: Original theme music by--

MARC SANCHEZ: Marc Sanchez.

TYLER: We had production help from the rest of the Brains On Universe team.

ROSIE DUPONT: Rosie DuPont.

ANNA GOLDFIELD: Anna Goldfield.

NICO WISLER: Nico Gonzalez Wisler.

RUBY GUTHRIE: Ruby Guthrie.

LAUREN HUMBERT: Lauren Humbert.

JOSHUA RAY: Joshua Ray.

MARC SANCHEZ: Marc Sanchez.

ANNA WEGGEL: Anna Weggel.

TYLER: And--

ARON WOLDESLASSIE: Aron Woldeslassie.

MOLLY BLOOM: Beth Perlman is our executive producer. And the executives in charge of APM Studios are Chandra Kavati and Joanne Griffith. Special thanks to Jen and Damo Lydiard.

TYLER: Brains On! is a non-profit public radio program.

MOLLY BLOOM: There are lots of ways to support the show-- subscribe to Brains On Universe on YouTube, where you can watch animated versions of some of your favorite episodes, or head to brainson.org.

TYLER: While you're there, you can send us mystery sounds, drawings, and questions.

MOLLY BLOOM: OK, Tyler, are you ready to listen to that mystery sound again?

TYLER: Yes.

MOLLY BLOOM: Awesome. Here it is.

[MYSTERY SOUND]

Last time you thought a nutcracker. Do you have new thoughts?

TYLER: I still think it's a nutcracker, and then they set it down. I've done that, and it sounds pretty similar to that.

MOLLY BLOOM: I love that. I think it's someone cracking a hard-boiled egg and then putting down another egg and then deciding that they actually don't want to eat the egg at all. I think yours is probably more right. Nutcracker sounds better. I'm going to go with nutcracker. Should we find out if we're right?

TYLER: Yes, we shall.

MOLLY BLOOM: Here's the answer.

ASHLYN: Hi my name is Ashlyn from Florence, Italy. And the sound you just heard was me putting my retainer on and then taking it off.

MOLLY BLOOM: Whoa. A retainer.

TYLER: Who would have guessed?

MOLLY BLOOM: Not us.

TYLER: Not us.

MOLLY BLOOM: I had a retainer back in the day. And what it is like a piece of plastic and metal that you put in your mouth to move your teeth or keep your teeth in the same spot, so like a lot of people will get them after they've gotten braces. They'll get a retainer.

So that person is taking their retainer out of their mouth. And then so I think that was the clicking sound, which we thought was a nutshell breaking, and then putting it down, which is what we thought the nutcracker was. So that's a tough one.

TYLER: It is.

MOLLY BLOOM: Yeah. My retainer, I'm not sad I don't wear it anymore. They get kind of gross, to be honest with you.

TYLER: I'm not sad I don't wear it yet.

MOLLY BLOOM: Definitely.

[MYSTERY SOUND]

Now it's time for the Brains honor roll. These are the kids who keep the show going with their questions, ideas, mystery sounds, drawings, and high fives.

[LISTING HONOR ROLL]

We'll be back next week with an extra special episode. We'll answer some of your "Is it true that" questions. Like, is it true Vikings wore helmets with big horns? And is it true that dogs can't see as many colors as humans?

TYLER: Thanks for listening.