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Grown ups Wondery subscribers can listen to wow in the World early and ad free right now. Join Wondery in the Wondery app or Wondery Kids plus on Apple Podcasts.
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Hey, Wowzer fams. Mindy and Guy Raz here. And before we start the show, did you hear that? We are on YouTube.
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That's right, Mindy. Wowzer fams. You can find full episodes of wow. In the World and more of your favorite Tinkercast podcasts on our YouTube channel, WowTube.
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Plus on WowTube, you can also watch me explode some watermelons and test out Bonkerball's experiments in the laboratory of bad ideas.
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Or you can dance along with Dennis for music videos featuring music from WEW on the weekend.
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There is so much in store made just for you on WowTube. Visit Tinkercast.com YouTube to watch. Now that's Tinkercast.com YouTube.
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Ew.
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Slimy squiggly little icky buggies. Flies and beetles and ants are so yucky. Nasty critters scurrying and squirming and wriggling and slithering and I'm gonna barf black.
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Creepy Crawly Week. Creepy Crawly Week.
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Things with wings and too many legs. Gross.
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Creepy Crawly Week. Creepy Crawly Week.
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Crawly Week. Crawly Week.
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Craw.
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Hello, and welcome to day two of Wee Wow. Creepy Crawly Week. I'm your host, Dennis, and I'm here with my co host, Reggie. Of course I sound grouchy, Reggie. I am grouchy because Mindy is making me watch her pet cockroach, Smokey McDougal all week and play wow. In the World episodes about bugs.
D
I hate bugs.
C
And speaking of, do we have any new instructions from Mindy?
D
Oh, gimme, gimme, gimme, gimme, gimme. Okay.
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Dear Dennis, Smokey needs plenty of exercise and he loves to play. Make sure he gets a chance to stretch all six of his legs.
D
Six? Reggie, no.
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Spiders have eight legs, and eight legs are cute. Oh, you're right. Smokey needs exercise and Mindy loves her pet. So I'll do it for Mindy. Uh, hey, Smokey, how's it hanging? I mean, Mindy says you like to play. How's about a nice game of catch? Oh, God, he wants to play catch. Reggie, what do we have that's small enough for Smokey to catch? Oh, good idea. Pocket lint. I think I have some here. There we go. Ready? Smokey want to catch the lint ball? Oh, right. Gotta take the lid off his tank first. Okay, Smokey, get ready to Catch and dance.
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No, no, no, no, no, no, no. Reggie. He climbed up the side and jumped right at me. Get him away. Get him away. Ah, he's chasing me. He's chasing me. Make him stop, Reggie. I don't know. Put on an episode of how in the World.
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Maybe it will lull him.
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I don't care which one. Just pick one. Yeah, sure.
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Invasion of the Zombie Ants.
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Fine, whatever. No, Smokey.
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Smokey, you stay down.
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Smokey, go.
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Wee. Wow. Will be right back.
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Grown ups.
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This message is for you. Hey, grownups, what happens when you bring a great white shark and a baby octopus to your house? A whole lot of wow. Hey, it's me, Mindy from Wow in the World, the number one science podcast for curious kids and their grownups. And we are so excited to bring the wows of sharks and sea creatures to your home without having to turn your house into an aquarium. Our jumbo great white shark is 24 inches long and comes with an exclusive wow. Fact card. Our baby ocean animals are perfect for the little ones in your life. Featuring exclusive audio that will leave the whole family saying, aw. These wow in the World toys make for fin tastic gifts for the kids in your life who love science and even the ones who don't. Yet grownups. Visit Tinkercast.com Toys to shop the wow. Now that's Tinkercast.com Toys. That's it. Now back to the show, wow in the World.
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And then I opened the cupboard, and when I turned on the light, I discovered that all my beans were de alphabetized.
D
Oh, no, Dennis.
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This isn't very scary guy. Raz, this was supposed to be a scary story.
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It is scary, Mindy. How am I supposed to find my chickpeas without an organizational system?
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Yeah, Mindy.
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Thank you.
D
Ugh.
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Okay, who else has a spooky story to share?
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Well, I can tell you the one about, does this look infected?
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Oh, no, please don't.
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Oh, I got one. It's a real spooker about a little goblin with arthritis in his knucks. Spoiler alert. The little goblin is me.
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No, Tommy, I want to tell the one about the Phantom of the Opera tickets that were all sold out. Reggie, it was so scary.
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What about you, Mindy? Do you have a spooky story to share?
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Well, I did just read a spooky scientific study in the journal Behavioral Ecology.
D
Too scary.
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It's not too scary. It's science.
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Hold me, guy.
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No, Dennis, go back to your chair.
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This story comes from a study conducted by researchers at the University of Copenhagen In Denmark, it's the story of a teeny tiny parasitic flatworm known as the Lancet liver fluke.
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I do not know what that is.
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Okay, well, a liver fluke is a.
E
Before that.
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Okay. A flatworm is a. Rewind farther. Okay. A parasitic flatworm.
E
Yeah, that.
B
What?
E
I do not know what that is. A parasitics. A paracritics. I don't know what you're saying.
B
Oh, okay. So a parasite is a teeny, tiny creature that must live on or inside of another living thing in order to.
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Stay alive and to survive. It takes nutrients from the other living thing.
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Yeah, a parasite is like a little thief.
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Well, I still don't get it.
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I can explain, Granny G. Huh? You can think of a parasite as someone who comes to visit your house and eats all your food and drinks all of your chocolate milk and steals all your friends and sleeps in your bed when you're away and uses your toothbrush and takes your money and finds your birthday card from your grandma and crosses your name out and writes his own in it. So it says, to Dennis, my number one granddaughter.
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Wait, that was you?
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No, it was an example of a parasite.
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Okay, I get it now.
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Dennis, did you use my toothbrush?
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It was an example.
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Mindy, are we still telling scary stories or. No.
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Thank you, Thomas Fingerling. Yes, we are. Now, where was I?
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I believe you were at the beginning, Mindy.
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Oh, right. Flashlight, please.
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Flashlight.
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Thank you. And now I submit to you the spooky yet scientific tale of the life cycle of the landset liver fluke. Once upon a time, on a warm summer day, a tiny ant was taking a leisurely stroll down the sidewalk.
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TRA la la boop doobie doo. I love being a tiny little ant.
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When he stumbled upon something delicious.
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Ooh, watch this now.
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It was a big honking lump of freshly coughed up snail mucus.
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Oo de lally. Snail mucus.
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But little did the ant know there was more to this snail mucus than he bargained for.
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This snail milk is sure is tasty. I wonder what the secret ingredient is.
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That secret ingredient. Hidden deep inside the snail mucus was an army of teeny, tiny parasitic flatworms known to scientists as the Lancet liver fluke.
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Hello.
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I'm a little liver fluke. Is everybody here?
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Yeah, baby. All here.
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Is this what an ant looks like on the inside?
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But these liver flukes were only in the larva stages of their little liver fluke lives.
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We're all babies. Waa wah wah.
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And in order to grow big and strong, these baby larva Liver flukes would need to find a liver.
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Hey, quiet, quiet.
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Does anyone see a liver around here?
D
No, I don't.
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See, we're inside an ant, and ants don't have livers.
D
Oh, okay.
C
Ants don't have livers. Well, we're gonna need to get to another living animal with a liver.
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But where in the world could these lowly liver flukes find a living liver?
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Moo, moo, moo. I'm a cow with a ripe old liver.
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That's it.
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A cow.
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But how could this army of liver flukes get from the inside of an ant to the inside of a cow? There was only one solution.
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There's only one solution. We need to get that cow to.
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Eat this ant that ate us.
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It's the only way to that liver. Okay.
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Hey, cow. Look, a delicious egg. Come on, cow.
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Oh, hold on a second. What?
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What do you want?
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The tiny liver fluke parasites were eaten by the ant?
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Yes, when the ant ate the snail mucus that the liver flukes were chilling in.
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And now that they're in the ant, they want to be eaten by the cow?
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Yes, because the cow has the liver that the liver flukes need to live off in order to grow and survive.
A
So wait, the best way to get the cow to eat the liver flukes is to get the. The cow to eat the ant?
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Yes, because the liver flukes are all inside the ant. So wherever the ant goes, the liver flukes go with it.
A
Okay, but how can they be sure that the cow will eat the ant?
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Well, if you'll allow me to get back to my story, I was just about to get to that part.
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Oh, right. Sorry. Please continue.
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Thank you. Now, the only way to get this ant eaten by the cow would be for the liver fluke to climb up, up, up into the ant's brain.
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What?
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Kat. Raz.
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Shh.
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Oh, sorry, sorry.
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Okay, I'll go up. The rest of you stay right here in the abdomen.
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You're so great. Thank you for saving us. You're our hero.
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While the army of liver flukes were in the abdomen, one brave parasite made the treacherous journey up, up, up into the ant's brain.
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Woo.
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Oh my goodness, so many stairs. Okay, here we are. The brain. Oh, wow.
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It was then that the liver fluke took control of the ant's brain once and for all.
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All right, just gotta hack into the mainframe and.
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Access granted.
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Haha.
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Napster, I'm in.
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Uh oh, that feels weird.
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It began sending instructions to influence the ant's behavior. You know, mind control. Tell it what to Do.
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Okay, let's see what this baby can do. Ant, scamper over that way.
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You got it. Scamper, scamper.
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Whee. Whee.
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Wow. The lancet liver fluke can tell the ant where to go.
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Yep.
D
Hooray. This is so fun.
C
Now put your hands in the air like you just don't care.
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That is so creepy.
B
Oh, creepy doesn't even begin to describe it, Guy Raz.
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Because, ooh, I'm a zombie ant now.
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Now, with control over the ant's movement, the liver fluke can get itself and the others into position, poised to be eaten by the cow.
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Okay, ant, climb that blade of grass over there.
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You got it, dude.
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Higher, higher, higher.
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Quit rushing me, Moo Moo Moo.
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I'm a hungry cow. This grass looks tasty. Maybe I'll just eat it.
D
Mm, mm, mm.
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I love eating grass.
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Okay, ant, stop right here.
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Yum, yum, yum. Right into my tum.
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And here we go.
D
Yum, yum, yum. We made it. We made it round, everyone.
C
We're the cow Merp.
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Moo.
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At this point, the army of baby larva liver flukes are taking a ride down the cow's digestive slide.
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We're up to see the liver, the wonderful liver of cow.
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La la la la la la la la la la la.
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Hold on. I'm sorry to interrupt. Mindy, come on. A liver fluke climbed into the ants brain, took control, and got the ant eaten by a cow.
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Huh?
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What?
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That's what she said. Boy.
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Moo.
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Mindy, this story is getting ridiculous.
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Ridiculous? No, no, no. This story is getting scientific, Guy Raz.
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But wouldn't the cow's stomach acids just destroy these tiny parasites?
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Well, you would think that would be the case, but the liver flukes have a plan for that too.
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They do? Yeah.
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See, they have this unique ability to form a hard shelled protective capsule around themselves. And the liver flukes huddle together inside that capsule and ride in it until they reach the liver.
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The liver flukes ride in a capsule through the digestive system all the way to the cow's liver.
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Moo Moo Moo.
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This just seems too wild to be true.
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What can I say, Guy Raz? Science is bonkerballs.
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That's one way to put it.
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But sadly, there is one liver fluke who will never see the light of the liver.
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Oh, yeah.
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With the army of liver fluke nestled safely in their capsule, their fearless leader realized that its time here had come to an end.
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My legion of larval liver flukes, I am sorry to Tell you. Tell you that my time here has come to an end. Yes, my work here is done. I made the treacherous climb of a lifetime. I took control of that ant's brain and turned it into a zombie. And I found you a liver to call home.
D
Thank you every single.
C
Yes, yes, I'm a big brave hero. But alas, my journey has come to an end.
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Fare thee well, my lovely larval liver flutes.
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I leave you in peace.
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The stomach acid I misses Just so sad.
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That liver fluke sacrificed its own.
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Life to help the others survive.
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At this point, the leaderless liver flukes have come too far in their quest to give up now. The liver is just on the other side of this highway of intestines.
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Come on everyone. I can almost smell that liver.
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Once we get through, the bile ducks will be there.
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They begin their treacherous journey, sailing through the sea of stomach acid, inching their way through an interstate of intestines as the capsule surrounding them dissolves. They're almost there.
D
We're almost there.
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Soon they make their way through the cow's bile ducts. And before they know it, they've reached the liver. The little larval liver flukes feast on the blood of the liver. And before long they grow big and strong. And soon they're fully grown. Flukes. Wow.
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Look how big and buff we are. Yeah, we're not babies anymore. Let's lay eggs.
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The liver flukes lay their eggs one. One by one. And then when the cow is done digesting.
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Oh, time to poop. Moo.
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The eggs are loaded up onto a cow poop barge and sent out to seek their fortune.
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Bye bye. Eggs make us proud out there. Oh, they grow up so fast.
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Wait, the eggs are just pooped out?
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Well, yeah, pretty much.
A
And then what?
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Well, they just hang out there in the cow poop waiting for a snail to come along and eat them.
E
So the snail just eats the poop eggs?
B
Well, the snail eats the poop with the eggs.
F
That is not how I like my eggs.
D
Me neither, Tommy.
E
I like my eggs scrambled, like finger length brains.
F
I like mine without poop all over em.
B
Okay, can we get back to the story, please?
A
Oh, maybe you can do that.
B
As I was saying, the liver fluke eggs lay in the poop waiting for a snail to come along and eat the poop with the eggs in it.
C
Um, Guy, I believe that's your line.
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What?
B
Yeah, you're the snail Guy. Raz, everyone's gotta play a part.
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Can't Reggie do it?
B
No. Not everyone can understand Reggie. So you have to do It.
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Okay, fine.
D
Yeah.
E
Eat the poop eggs.
B
Garage.
A
Okay.
D
Mm, mm, mm.
A
What is this? A fresh pile of cow poop with eggs inside. Yum yum. Don't mind if I do.
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And once the snail eats those eggs. Jackpot. The eggs develop into larval baby flukes and reproduce or multiply until there are several thousand of them.
D
We're new baby larval liver flukes.
B
And soon those baby larval liver flukes are ready to move on.
D
Who's ready to move on up?
B
And when the time is right, the snail oozes out a big lump of snail mucus.
D
Ahem.
B
Guy Raz, it's you.
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Oh, sorry.
E
What is he doing? Is he okay?
A
Sorry, sorry.
B
A slime ball filled with baby larval liver flukes oozes out of the snail and is left on the ground just waiting to be eaten. Eaten by an ant.
F
TRA la la boopy doobie doo. I love being a tiny little ant Rood a lolly snail mucus.
B
And thus the circle of life of the liver fluke begins anew. The end.
A
That was a really disturbing, disturbing story, Mindy.
B
Why, thank you, Guy Raz.
F
I thought the ant was the best part. You know, the way it ate the snail. Snot full of little baby liver flukes.
C
And I thought that the one heroic liver fluke was the best part. The one that controlled the ant's brain and turned it into a zombie and made it get eaten by a cow.
E
And I thought that the cow was the best part. Cause it ate the ant filled with them liver flukes and then got them to crawl around its liver and suck its blood and pooped them all out when the party was over.
A
And I kind of enjoyed the part of the snail when the snail came upon the cow feces filled with the liver fluke eggs and. Okay, yeah, I didn't enjoy that part either. Too gross.
F
Well, that was a good spooky story, Mandy.
A
Yeah.
C
And how did you come up with the part about the liver fluke hijacking the ant's brain?
B
Oh, I didn't, Dennis. In fact, I didn't come up with any of that story on my own. These were act scientific observations made by researchers at the University of Copenhagen in Denmark.
C
Nuh.
B
It's true, Dennis.
A
Yeah, Sometimes science can uncover truths about our world that seem like spooky stories.
B
And sometimes science is stranger than anything we could possibly make up ourselves.
F
Gnarly.
E
Well, I'm hungry. Anybody else still thinking about that snail mucus?
D
No.
B
Grownups, if you like. Wow. In the world you can listen early and ad free right now on Wondery.
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Join Wondery in the Wondery app or on Wondery Kids plus on Apple Podcasts. Prime members can listen ad free on Amazon Music.
B
And before you go, tell us about yourself by filling out a short survey@wondery.com.
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Wow in the world is written by Mindy Thomas and Tom Van Kalken with help from Me Guy Raz.
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Original sound design and music editing is done by our senior Production Director Jed Anderson and Audio Producer Tyler Thull. You can also hear Jed Anderson in the voices of Dennis Thomas, Fingerling, Reggie and many of the other silly characters that you hear here on our show. And Lizzie Froehlich can also be heard as some of the silly characters on our show.
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Jessica Bode keeps our facts straight as our fact checker and Meredith Halpert Ranzer powers the WOW at Tinkercast.
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Our theme song was composed and performed by three time Grammy nominees the Pop Ups. Find them at thepopups.com Special thanks to.
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Kit Ballinger, Rebecca Caban, Dr. Natasha Crandall, Kenny Curtis, Kristin Yang, Twee Mac, Erica Medina, Henry Moskal, Jody Nussbaum, Ali Paxima, Linda Rothenberg, Steph Sosa, Joanna Weber, Anna Zagorski and all of the other tinkerers at Tinkercast HQ.
B
And to keep the wow rolling after you've finished this episode, visit us@tinkercast.com There you can become a member of the World Organization of wowzers to get year round mailings and weekly activities. Shop our wow Shop, get tickets for upcoming events, find our best selling books and learn about some of the other amazing podcasts from Tinkercast grownups.
A
You can follow wow in the World on Facebook, Instagram and Twitter @wowintheworld. And our email address is hellonkercast.com and.
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If you're a kid with a big wow to share with us, call us at 1-888-7-WOW-WOW for a chance to be featured at the end of our show or an upcoming episode of 2 what's in a wow?
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Thanks again for listening. We're here every Monday or you can check out two what's and a wow every Friday right here in the wow in the World Podcast feed.
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And don't forget we WOW on the weekend with Dennis Saturday and Sunday.
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Keep on wowing.
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Wow in the World was made by Tinkercast and sent to you by Wondery.
Release Date: October 28, 2025
Hosts: Mindy Thomas & Guy Raz
Featured Characters: Dennis, Reggie, Granny G, Tommy Fingerling
Day 2 of Creepy Crawly Week turns the spotlight on some of the “grossest” and most fascinating insects and parasites in the natural world. Mindy and Guy Raz, joined by Dennis, Reggie, Granny G, and Tommy, explore the bizarre real-life tale of the lancet liver fluke—a parasite that turns ants into ‘zombies’ to complete its wild life cycle. The episode is told in a fun, storytime format with plenty of gross-out humor and dramatic performances, all rooted in actual scientific research to help kids and their grown-ups marvel at how strange and innovative nature can be.
“Well, I did just read a spooky scientific study in the journal Behavioral Ecology.”
— Mindy (06:02)
“A parasite is like a little thief.”
— Mindy (07:14)
“Now, the only way to get this ant eaten by the cow would be for the liver fluke to climb up, up, up into the ant’s brain.”
— Mindy (11:39)
“They have this unique ability to form a hard-shelled protective capsule around themselves.”
— Mindy (15:52)
“A slime ball filled with baby larval liver flukes oozes out of the snail and is left on the ground just waiting to be eaten by an ant.”
— Mindy (21:29)
“I didn’t come up with any of that story on my own. These were scientific observations by researchers at the University of Copenhagen in Denmark.”
— Mindy (23:04)
Creepy crawlies like the lancet liver fluke have some of the weirdest, most clever survival strategies in the animal kingdom—and their life cycles are real, not science fiction! Science, Mindy reminds us, is sometimes weirder and wilder than our wildest stories.