Ask Dr. Universe

Episode 6: Flying Squirrels, Curious Pets, Frosty Patterns, Stinky Cheeses

February 23, 2021 Washington State University
Ask Dr. Universe
Episode 6: Flying Squirrels, Curious Pets, Frosty Patterns, Stinky Cheeses
Show Notes Transcript

On this episode, we'll explore questions about flying squirrels, our curious pets, frost, and stinky cheese. A big thanks to our kid narrator from Regional Theater of the Palouse. Thanks to everyone who helped with the science on this episode: Todd Wilson, Dr. Jessica Bell, Kai Carter, and Minto Michael.

Submit a science question at for a chance to be featured on a future episode. 

Dr. Universe  0:04  
Welcome back, young scientists. I'm Dr. Universe and if you're anything like me, you've got lots of big questions about our world. On this episode, we'll explore questions about flying squirrels, our curious pets, frost, and stinky cheese. A big thanks to our kid narrator from Regional Theater of the Palouse. RTOP is a proud sponsor of STEAM learning. Discover the art of science, technology, engineering, and mathematics. STEM makes life possible and art makes it worth living. Support your local arts and humanities programs. Together, STEM is gaining STEAM. Let's get started.

Aadi  0:40  
Hi, I'm Aadi an RTOP theater kid. Gwendolyn, age 9, asks, Dr. Universe, Do flying squirrels really fly?

Dr. Universe  0:49  
When flying squirrels are trying to avoid predators, like weasels, sometimes they'll run to the top of a tree. The weasel might think that the flying squirrel has nowhere else to run. But that's when the flying squirrel makes its move. 

Todd Wilson  1:02  
And the flying squirrel can just take off and glide. 

Dr. Universe  1:05  
That's Todd Wilson, a wildlife biologist with the US Forest Service in Oregon, and a graduate of Washington State University. He researches Pacific Northwest ecosystems and the animals that call them home. Like flying squirrels. Flying squirrels don't fly, but they do glide sometimes for hundreds of feet. How do they do it?

Todd Wilson  1:25  
They have an extra flap of skin between their front and their back legs on either side. And so it functions sort of like a parachute. They use their tail like a rudder. And they can actually go in- between and trees around trees while they're gliding.

Dr. Universe  1:41  
Have you ever seen a flying squirrel out in the field before? And if so, what was that like?

Todd Wilson  1:45  
It was like "Wow, that is absolutely cool to watch them glide, especially leaping off a very tall old-growth tree."

Dr. Universe  1:51  
Flying squirrels are not only cool, but Wilson said they also play a big part in the environment. Can you tell us a little bit more about what they eat and how that helps the forests?

Todd Wilson  2:02  
You've got two different kinds of fungi, you've got the above-ground fungi that we call a mushroom, that's the fruit. There's also a whole bunch of fungi that are below the ground. 

Dr. Universe  2:12  
The ones below ground are called truffles, and flying squirrels love to eat them.

Todd Wilson  2:17  
And the only way that they can spread and help the forest is by animals digging them up and smelling them and eating them. 

Dr. Universe  2:26  
Enter the flying squirrel. As the flying squirrels eat the fungi, they spread the fungi around through their, well, their poop. Then what did the fungi do? 

Todd Wilson  2:38  
And those fungi are critical for the trees. They help suck up nutrients from the soil and pass them to the tree. And in exchange the tree gives them some sugars. And that's what the fungi like. And so without the fungi, we would have no trees in the northwest except for maybe the cedars. Everything is really linked in these ecosystems. Flying squirrels are pretty cool example of that relationship.

Dr. Universe  3:02  
Thanks for telling us about flying squirrels. All right, young scientists, there's only one mammal that can actually fly. Can you guess what it is? Of all the mammal species on our planet bats are the only true fliers.

Aadi  3:17  
Speaking of mammals, our next question is about some other members of this animal group. Antonio, age, 10 in Richmond, Virginia, asks, Dr. Universe, Why do dogs and cats spin around before they sit down?

Dr. Universe  3:34  
That's a great observation about cats and dogs. Even I wasn't sure why cats spin around before they sit down. So I took your question to my friend Dr. Jessica Bell. She has seen quite a few cats and dogs walk in a little circle before they sit down. 

Jessica Bell  3:48  
I'm Jessica Bell. I'm a veterinarian at Washington State University in the Veterinary Teaching Hospital. There's lots of reasons why and probably every dog and cat has a different reason. Granted, we can't talk to them and ask them questions like "Why?". But from a behavioral standpoint, it probably stems back to the wild instinct. 

Dr. Universe  4:07  
Have you heard of instincts before young scientists? Migrating birds, web- spinning spiders and even our own pets have instincts? An instinct is a behavior that animals don't have to learn. They're born with this behavior, and it helps them survive in the world. 

Jessica Bell  4:24  
And so they often position themselves the same position on their bed every time. They want to face the direction of escape or a predator coming at them. That's part of their instinct is to still follow that. That's probably your more scientific reason. But I think many of our domestic dogs and cats they really are just finding good comfy fluffy spot to lay and they've got to get it just right. 

Dr. Universe  4:45  
Thank you so much, Dr. Bell. Just thinking about curling up in a comfy spot is making me want to take a nap. But there's no time for naps. We have more questions to answer. Here's the next one.

Aadi  4:57  
Grace age 13 in Calgary, Canada, asks: When frost freezes it makes up shapes like flowers and ferns. Why does it look like that?

Dr. Universe  5:07  
Our friends at WSU's Ag Weather Network are always great to talk to about weather questions.

Kai Carter  5:13  
My name is Kai Carter, I'm a field meteorologist for WSU Ag Weather Network. What is frost? Frost is water in the air. So humidity that comes in contact with a surface that is below the freezing temperature.

Dr. Universe  5:28  
Freezing temperature is 32 degrees Fahrenheit.

Kai Carter  5:32  
And if the surface is below the freezing temperature, then the water will freeze to that surface. When these water molecules meet and freeze, they tend to make hexagonal structures.

Dr. Universe  5:44  
We also see this in snow right?

Kai Carter  5:46  
In the center of a snowflake is almost always a hexagon.

Dr. Universe  5:50  
In frost, the water molecules freeze and join together in a sort of hexagon-shaped ring with other water molecules to form all kinds of patterns of ice crystals

Kai Carter  5:59  
On flat surfaces, there's all these little imperfections that we can't see. There's dust and scratches and lots of variation that channels those molecules together so that they meet and then they will impact how the structures grow.

Dr. Universe  6:16  
As you've observed, these structures can start to branch out into shapes that might look to us like feathers, or ferns, or tree limbs. In mathematics, we call this kind of thing a fractal design. A fractal pattern repeats itself at different scales. One other place you might find fractal patterns is in ferns. The fern frond looks like it's made up of little fern fronds which look like they're made up of even smaller fern fronds. Next time you see some frost take some time to observe its detailed patterns with a magnifying glass.

Aadi  6:46  
Even if you don't live someplace where it gets really cold, you can actually make frost right in the kitchen. All you need is a tin can. Salt and ice. Fill the tin with ice and four tablespoons of salt. Mix it up for a minute. Wait a few minutes and see what forms on the outside of the tin. The salt is important because it melts the ice while also helping the mixture drop below freezing. Why do you think that might be? What happens when you add more salt or more ice? Have fun with your frosty experiment scientists. Here's our final question for this episode. Cody age 11 asks, Dr. Universe Why do some cheeses stink?

Dr. Universe  7:32  
When you take a whiff of stinky cheese, that smell is coming from one of its very important ingredients microorganisms. I took your question to one of our professors here at WSU to find out more about it. 

Minto Michael  7:46  
My name is Minto Michael, I'm an assistant professor of Dairy Science in the School of Food Science at Washington State University. 

Dr. Universe
What can you tell us about cheese?

Minto Michael
Cheese is in general can be made in two ways. The first way is a very simple way you take milk you heat it up and you add acid something like citric acid.

Dr. Universe  8:04  
The milk coagulates or becomes more like a solid. Then the cheesemakers can separate the solid curds from the liquid whey.

Minto Michael  8:11  
And these are normally fresh cheeses that you make and you consume within few weeks. The other type of cheeses are where we actually use microorganisms, specifically lactic acid bacteria to make cheeses.

Dr. Universe  8:24  
If you remember a question about microbes from Episode One, you know they are so small you wouldn't need a microscope to see most of them. We can trace the flavors and aromas of cheese back to microorganisms.

Minto Michael  8:37  
So what we do is we take milk we pasteurize it,

Dr. Universe  8:40  
That is, heating it up to kill any bad bacteria that can make us sick.

Minto Michael  8:45  
So we take milk pasteurized it and then we add lactic acid bacteria. So what happens is this bacteria consumes milk sugar and produce lactic acid.

Dr. Universe  8:55  
Lactic acid bacteria help the milk get ready for another ingredient called rennet an enzyme which helps the turn the milk from a liquid state into more of a solid that will become cheese. While the lactic acid bacteria may do a lot of work to help make the cheese there are benefits to the job.

Minto Michael  9:10  
So these microorganisms what they do is they eat up the milk, sugar, milk proteins and milk fat, so that they can consume this produce energy and multiply.

Dr. Universe  9:24  
As they eat, they also produce a stinky gas. The gas is made up of different chemical compounds, especially carbon dioxide, nitrogen, ammonia, or other sulfur-based compounds.

Minto Michael  9:35  
Once the cheese is made, we aged it. We store the=e cheese for few months to few years. So during this aging process, these microorganisms continue eating sugars, proteins, and fat.

Dr. Universe  9:48  
And they keep making gas the smells and flavors and the cheese get even stronger. While some gases are responsible for smells and flavors, other gases can give cheese texture. Carbon dioxide is a big part of the reason Swiss cheese has holes.

Minto Michael  10:00  
It bursts the structure of the cheese. It doesn't impart that much of bad smell, but the gas is formed in so much quantity that it forms holes.

Dr. Universe  10:11  
One of my favorite non-stinky cheeses is made here at WSU. It's called Cougar Gold and it comes in a can. The microorganisms that go into it are part of a top-secret recipe. We might not be able to reveal the secrets here on the podcast, but there's at least one thing we do know.

Minto Michael  10:29  
They just produce good, tasty, aroma and flavors in the cheese.

Dr. Universe  10:35  
That's all for this episode, friends. Thanks to all the kids who submitted a question. To Aadi, our RTOP kid narrator for that great narration and to Washington State University researchers for helping with the science. And of course, thanks to you for listening. You make this podcast possible. As always, you can submit a science question of your own for a chance to be featured at that's a-s-k-d-r-u-n-i-v-e-r-s-e dot w-s-u- dot e-d-u. Who knows where your questions will take us next.