Friends, we are so super duper excited to tell you that we just added a bunch more cities to our 2026 live show tour.
Get ready for singing dancing, magic tricks, game shows, mystery sounds and scientists falling from the sky in a totally safe way.
We promise.
Plus, there's a chance for you to attend special meet and greet parties in every city.
So come on.
This spring, we're coming to Milwaukee, St.
Paul Atlanta, Fort Lauderdale Chattanooga Durham, San Francisco Portland Buffalo, Toronto and Ann Arbor.
We're basically gonna be everywhere.
Look behind you.
Are we there?
No?
Well, we probably will be soon.
Head over to brainson.org slash events for tickets.
And make sure you grab passes to our meet and greet party.
You get to ask us questions, take pictures with us, and I'll even do some close-up magic.
That's brainson.org slash events.
Can't wait to see you.
Brains on Universe.
You're listening to Brains On where we're serious about being curious.
Noses exist for lots of reasons.
They help us breathe.
Mine hold up my glasses.
I like to try and wiggle mine.
But one of a nose's most important jobs is to smell stuff.
Maybe that's why noses love roses.
Roses are actually one of the most complex smell mixtures we know of.
Some studies by scientists like me have shown that roses can make up to 200 different smell chemicals in their smell.
Roses and other flowers aren't pumping out those pretty perfumes for us, though.
It's for bugs and birds.
And sunflowers make a stink so strong it'll make you wish your nose had an off button.
Flowers and the science of their scents, coming up.
Oh hey, do you mind grabbing that bag of trash?
Thanks.
It's my turn to take out the trash.
We have a chore wheel.
Sanding got removing cobwebs this week, which is my favorite.
You get to use the suction shoes and walk on the ceiling.
So fun.
Anyway, can you hand me that bag now?
Thanks.
When everyone pitches in, things just work. which is why we love when people join Smarty Pass.
It funds our research, our writing, our sound design, and so much more.
Plus, you get access to ad-free versions of all our shows, invites to special online hangouts with us, merch discounts and tons of other things.
Go to brainson.org slash smartypass to help out.
Okay, time to go back inside.
You can think of joining Smarty Pass as you doing your part to make this show happen.
Thank you.
Hey, Mark.
I saved a cobweb up there for you.
Want to go put on the suction shoes and go get it?
Oh, yeah, buddy.
Thank you.
You're listening to Brains On, part of the Brains On universe.
I'm Molly Bloom, and my co-host today is Isla from Melbourne, Australia.
Hi, Isla.
Happy to be here, Molly.
Today, we're answering these questions about flowers.
My name is Elise from San Diego, California.
My name is Griffin from Santa Rosa, California.
Hi, my name is Vivian.
From St.
Louis, Missouri.
My question is, how do flowers make their smell?
How and why do flowers smell?
How do flowers get their smell?
Isla, are there lots of flowers where you live?
Yeah, Melbourne has lots of flowers.
There's a whole botanical garden near me that I like to go to with my sisters.
Oh, fun.
Do you have a favorite flower?
My favorite flower is probably one of the native flowers called a banksia.
It kind of looks like a porcupine.
Oh, I want to see that flower.
So is there a flower that you feel like kind of like represents you or like it's kind of, you feel like a kinship with?
I think maybe a sunflower because it's my favorite color and it's bright like me.
Oh, I love that.
So besides flowers, what are some of your other favorite smells?
Probably chocolate, dinner, and I have a coconut perfume that I like.
And how about some of your least favorite smells?
Dad's socks.
Dad's socks.
Stinky socks yeah, no one likes that.
Um, do you feel like your dads are stinkier than other socks you've smelled?
Yeah.
So do you have a favorite flower smell?
Um, i like roses.
They smell really nice.
Yeah, they do.
I put a new one in my room every week.
Oh, that's so nice.
I think my favorite is probably lilac.
They bloom here for only a very short amount of time, but when they do, it's very, very wonderful.
Flower aroma is a terrific topic.
To get started, let's review some flower basics.
Flowers are a part of many plants.
And aside from looking great and smelling great, flowers have a super important job.
Flowers are how these plants make more of themselves.
The flowers will eventually make seeds that will grow into new flowers.
But for a flower to make these seeds, it needs to be pollinated.
That involves, you guessed it, pollen, that powdery stuff inside flowers.
To make seeds.
That pollen usually needs to be moved from one flower to another flower of the same kind, sort of like moving a key from your pocket to a lock.
When the key and lock finally meet, it opens a door.
For a flower, the pollen is like the key.
In the middle of a flower is a part called the stigma.
That's like the lock.
When pollen from one flower makes it to the stigma of another flower, it unlocks the process of making seeds.
But the pollen and the stigma have to be from the same type of flower.
Pollen from a rose, for instance, can't pollinate a daisy.
Yeah, that's like having the wrong key for the wrong lock.
So, what helps move all that pollen around?
Most of the time, it's animals called pollinators.
Let's meet them.
Pollinators, calling all pollinators, it's the Pollinator Report.
Pollinators are animals that visit flowers.
They're usually looking for nectar or pollen they can eat.
While there, they get pollen on their bodies.
Then they carry the pollen with them when they visit the next flower.
Pollination accomplished.
The most common pollinators are bees, flies, butterflies, and moths.
But other animals can do it too, like ants, bats, birds, lizards, and even small rodents.
Some flowers can pollinate themselves, and even a strong breeze or water can move pollen around.
But for the most part, this important work is done by tiny creatures all over the planet, working day and night.
Thanks, pollinators!
Calling all pollinators, calling all pollinators, this is what we call flower pollination.
Since pollinators are so important, flowers have developed all kinds of ways to get them to come visit.
Sometimes they attract pollinators by looking exciting, but a lot of the time they use smells.
So smell is basically little bits of chemicals floating around in the atmosphere around us.
That's Dr. Kelsey Byers.
She studies flowers and their smells at the John Innes Center in the United Kingdom.
So when you breathe in that air into your lungs and it travels over your nose, you can imagine breathing in.
All those little particles of smell are floating around in the air and they're getting stuck to your nose.
So flower smells are just really small bits of chemicals released by flowers.
When those chemicals are in the air, animals can sense them.
We sense them through our noses.
Kelsey says flowers often make those chemical smells in the petals themselves.
But sometimes the smell can also come from the leaves.
If you've ever smelled herbs or spices, for example.
Or it can come from the nectar, which is what the plants use to feed their pollinators, like bees.
So it can come from any part of the plant, but most often it's coming from the petals.
Wild mystery alert.
It turns out scientists don't know exactly how most flowers release these smells.
Are there tiny openings on the petal?
Or do the smells evaporate out?
Does it spray like perfume?
Maybe one of you listening will figure it out.
Some flowers have simple smells made up of just a few chemicals.
But not roses.
Roses are actually one of the most complex smell mixtures we know of.
Some studies by scientists like me have shown that roses can make up to 200 different smell chemicals in their smell.
And we call that a bouquet, just like a bouquet of flowers is not just the individual flowers but that whole beautiful bouquet you hold.
A smell bouquet is not just the individual smell chemicals but the whole picture of all of them together.
And our brains actually process those, not just by going well, that one's this smell and that one's this smell, but they actually mix together to create a unique picture in our brain of what a rose smells like.
So flowers make smells to attract pollinators, but sometimes they make smells to get rid of bugs.
We'll explain in a minute, but first, another wild mystery alert.
It's the... Ayla, are you ready for the mystery sound?
Yes.
Wonderful.
Here it is.
Maybe it kind of sounds like someone scraping a carpet or something.
Like maybe cleaning something.
Very good.
Do you want to hear it again?
Yeah.
Okay, so you thought cleaning.
What's another thought?
Maybe brushing something.
Like maybe metal.
Ooh, nice.
With a brush.
Very good.
Okay, we'll hear the mystery sound again.
Get another chance to guess and hear the answer after the credits.
So stick around.
We are working on an episode about the science of baseball.
And if you've ever been to a game, you know there are some great chance.
Like when twins...
But you know what doesn't have a lot of chance?
Science.
So let's make some.
Hilah, if you had to come up with a chant or cheer for science, what would you say?
Maybe something like, we like science.
Yes, we do.
We like science.
How about you?
Oh, I really like that.
And it had a really good rhythm, too.
Listeners, send us your science cheers, record them and then go to brainsonorg slash contact to send them our way.
That's also where you can send questions, mystery sounds, drawings or tell us your favorite science-themed joke.
Again, that's brainson.org slash contact.
We can't wait to hear from you.
Welcome back.
This is Brains On, and I'm Molly.
And I'm Isla.
And we just learned how flowers get their smells.
It's chemicals.
Flowers make special chemicals and release them into the air.
The goal is to lure in pollinators.
So if all flowers are pretty much trying to do the same thing, why do different flowers have different scents?
Here's flower smell researcher Kelsey Byers again.
So different flowers have different smells because the smells are serving different purposes.
So, for example, say that you want to attract a honeybee and you want the honeybee to come and move your pollen from one flower to another flower.
Ideally, you would smell like something that smells good to a honeybee.
But let's say you're a type of flower that's best pollinated by a moth.
Then you'd want to smell good to moths.
Sunflowers make smells that lots of pollinators like dandelions, for example.
But sunflowers want very specific pollinators to visit, like orchids that can only be pollinated by a certain type of wasp.
Those orchids will make a smell that's really only attractive to that wasp.
So flowers make different smells to attract different pollinators.
Cool stuff.
But it gets even cooler because flowers can also change their smell over time.
Here's Kelsey.
So one of the biggest changes that we've noticed is that many flowers change their smell after they've been pollinated.
So after an insect has come to visit them to move pollen around.
And some of the idea we think behind this is that if you've already got enough pollen to make seeds, there's no point in having an insect visit you anymore from the plant's point of view.
There's even some flowers that will start smelling bad to pollinators after they've been pollinated.
So they go from a smell that says, Yoo-hoo!
Come here!
Come over here! one that says, ew, go away, leave me alone.
That way, if a fly or bee comes by, they won't pollinate a flower that's already pollinated.
They're more likely to keep looking for a flower that hasn't been pollinated yet and still smells good.
That helps more flowers get pollinated.
So clever.
Well done, flowers.
Oh, thank you.
Let's take a quick break and check out the mailbag.
This is where we dive into all the cool questions, drawings, and ideas you send our way.
Looks like we've got some more designs for new rooms at our brand new headquarters.
Let's see what these creative architects have dreamed up.
I think a new room for the Brain John Headquarters should be a robot room, with those robots that do different tasks for you.
And I think you should have a room where there's trees connected to rockets and you can send a tree into space.
And my idea for a new room and brains on headquarters is a cosinator, so it would be a room when you walk in and there's a keypad and then you type up something that you think is cozy, like a snack or a pillow or a blanket or a beanbag chair or a stuffy or something cozy, and then it appears when you're done typing.
Then you can just turn it into your cozy room and you can snuggle up.
That was Cyril, Benji, and Charlotte.
I want to snuggle up to all these new spaces.
Send us your idea for a new Brains On headquarters room.
Go to brainson.org slash contact to let us know what you come up with.
See you next time.
Brains On is supported by you because people like you keep us going.
Join Smarty Pass to power more episodes.
Plus, you'll get access to our ad-free feed so you get all our shows with zero breaks.
Thanks.
Welcome back.
Isla and I are talking about flower smells.
Those wisps of air that are actually invisible messages made of chemicals.
Flowers use these chemical messages to attract animals and sometimes to drive them away.
Speaking of driving away, shoo, fly, shoo!
How did that fly get in the studio?
Ish, it's flying in my face.
Help me get it away.
BANG!
Did someone call for help?
Hey, Sandon.
Ugh, what's that smell?
It's me.
I haven't showered in two weeks.
I'm wearing clothes I got from the dumpster, and I gargled expired milk before I came over.
Um, why?
So I can keep up with my team.
Your team?
Yeah.
Meet the super team I assembled.
We're called Stink Force.
Stink Force!
Stink Force!
To my left, Captain Skunkterpants.
Is that a real skunk?
Yep, but I only stink when startled or when the world needs saving.
To my right, we have Titum Arum, codename Corpse Flower.
Hello.
Over here, the eight-foot-tall, big red flower, that's me.
Hi.
Hi.
Wow, a corpse flower.
I've heard of these.
They are real flowers that grow in jungles and let off a famous foul odor.
Aww, you're making me blush.
Together, we save the world using the power of stink.
If a bad guy's robbing a bank, we put stank in that bank and leave that thief gasping for fresh air.
If there's a cat stuck in a tree, We stink so hard, the cat takes one whiff and passes out.
Then we catch it as it falls.
Cat rescued.
And if there's an old lady who needs help crossing the street, we help her.
While smelling terrible.
Stink force!
Well, it worked.
The fly left me alone and landed on the big corpse flower.
Yeah.
Flies love me.
I smell like, uh, rotting flesh, Limburger cheese, garlic, all the dankest stanks.
Yeah, you sure do.
Yeah, why exactly do you do that again?
It's how I attract the right pollinators.
You see, some flowers like to attract regular old pollinators, like butterflies or birds.
But I specialize in attracting beetles and flies that like rotting meat.
Yeah, it's kind of genius, actually.
The corpse flower grows in jungles, and it can get really, really big.
Yeah, it looks like a giant flower that's about as tall as a school bus.
Exactly.
It takes a lot of work to grow that big, and it can take years for the flower to bloom, too.
And when they do bloom, it only lasts for like a day or two.
So a corpse flower needs to make sure that it can attract all the pollinators it can in a very short amount of time.
Yeah, that's why my stink is so strong.
I want to lure in rotten... flesh-loving beetles and flies from all over.
My smell can travel around three miles.
That's serious stinkage.
Oh, and get this.
Part of the flower even heats up during the bloom.
This helps waft out that scent, and it makes the flower seem more like a warm dead animal corpse.
That's actually so clever and sneaky.
Very.
So a fly or beetle will come to the flower, thinking they'll find a good place to lay their eggs, so their larva can eat the dead meat when they hatch.
Yep.
But instead, they find a flower.
They pick up pollen, move it around and hopefully pollinate a corpse flower and help make more of these marvelous plants.
There are a handful of other flowers that also use stink to attract pollinators.
But in my opinion, the corpse flower is by far the coolest.
I agree.
So cool.
Yeah, you are a fascinating flower.
What can I say?
It's all thanks to my stanks.
But speaking of stanks, do you think you could find someone else to help now?
It's getting a little hard to breathe in here.
Oh, of course.
Come on, little fly.
Let's leave these nice people alone.
Great work, team.
Another day saved by Stink Force.
Stink Force!
Flower smells are just chemicals that a plant releases into the air.
These smells help attract birds, bees, moths, and other animals.
Those animals pick up pollen from one flower and help move it to another flower of the same kind.
That kicks off the process of making flower seeds, so even more flowers can grow.
That's it for this episode of Brains On.
This episode was produced by me, Molly Bloom, Mark Sanchez, and Santa Totten.
It was sound designed by Mark Sanchez, who also wrote our theme music.
We had engineering help from Derek Myers.
Special thanks to Tom Brandt, Adeline and Celeste, and Fiona Clark.
And special thanks to Ken Taborski at Code of the North for all of their website help.
Okay, Isla, let's hear that mystery sound one more time.
Earlier you thought someone sweeping something, maybe cleaning, maybe a brush on something.
Do you have new thoughts?
Not really.
I think I might stay with the same guess.
Okay, I like your guess.
Should we see what the answer is?
Yes.
All right, here is the answer.
Hi, I'm Charlotte and I'm from Annandale, New Jersey.
That was the sound of a paint roller going on a wall.
Okay.
Okay.
I am giving you at least partial credit, maybe even full credit, because a paint roller is essentially like a paintbrush and you said brush.
That was hard.
That was really hard.
Have you used a paint roller before?
No.
Have you seen one?
Do you know what they look like?
Yeah, like the rollers with the long stick thing.
Exactly.
And there's like kind of like a spongy thing on the end that you roll on the wall.
So it's like a sponge rolling paint on the wall.
I think you did great.
That was a hard one.
Now it's time for the Brain's Honor Roll.
These are the incredible kids who keep the show going with their questions ideas, mystery sounds, drawings and high fives.
Vivian and Louis from Maplewood, Minnesota.
Annie from Ann Arbor, Michigan.
Hayden from Lexington, Massachusetts.
Hunter from Texas.
Jameson and Owen from Cottonwood Heights, Utah.
Anderson and Cordelia from Creston, California.
Ethan from Hartford, South Dakota.
Annie and Patty from Gladwin, Pennsylvania.
Sinwo from Baoding, China.
Jerry from Mexico City.
Rita from North Brand, We'll be right back.
Susanna from Nashville, Amelia, Micah, and Felicity from Duluth, Minnesota, Philip from St.
Paul, Minnesota, Felix from Union City, California, Molly and Dinah from St.
Paul Minnesota, Alex from Revelstoke, British Columbia, Mana from Osaka Japan, Will from Simsbury Connecticut, Henry and Sammy from Ladysmith, British Columbia.
Evan from Rochester, New York.
Ali and Fern from Alberta, and Emmy from Yerevan, Armenia.
We'll be back next week with a new episode of Hoax Hunters.
Thanks for listening.
