Cosmo
Hey, Doctor Universe. Why did the germ cross the microscope?
Dr. Universe
Hmm. I don't know. Why?
Cosmo
To get to the other slide.
Dr. Universe
Today we're answering a question from Prince, age 12, in Georgia. Who wants to know: Why do we have germs on our hands?
Cosmo
Ooh, germs. Are they fun guys?
Dr. Universe
Well, some of them. They're also called microbes. They're tiny living things like bacteria, viruses, and your fungi. Microbes are so small you need a microscope to see them. Some germs can make us sick, but others don't bother us at all. And some even help us.
Cosmo
Okay, but how do they end up on my paws?
Dr. Universe
Well, we pick them up from the world around us where they're just hanging out, minding their own business. Like when we dig in dirt, touch rocks, or splash in rivers. Some microbes even float around in the air. They can stick to our skin if we bump into them. And we use our hands a lot, so that's where lots of them wind up. Sometimes germs come from other people. Like if someone sneezes or coughs, germs come out with their spit and snot.
Cosmo
Ew. So if someone coughs on me, their slimy germs get on me?
Dr. Universe
Or maybe they sneeze or cough on something like a table, and then you touch that table and pick up their germs. Or maybe they use their hand to politely cover their cough, but then they use that same hand to touch a doorknob or something.
Cosmo
Ew. They should wash their paws.
Dr. Universe
Soap and scrubbing send most germs right down the drain.
Cosmo
Good.
Dr. Universe
But here's the thing. Some microbes live on our skin all the time. They live on our hands. And they live in moist, cozy spots like your belly button.
Cosmo
Gross. I should have expected something like that.
Dr. Universe
Microbes need the same things we do: space, shelter, water, and food. They tuck themselves into crevices like the gaps in between our skin cells. They chow down on tasty stuff on our skin like oils and sugars. And by taking up space and using resources, they help keep out the germs that don't belong.
Cosmo
So we like those guys?
Dr. Universe
Yeah. There are even microbes that live inside your guts and help you digest your food and stay healthy.
Cosmo
Oh that's nice.
Dr. Universe
But they can leave your body when you use the bathroom, and it's not good to get even those friendly germs in other places like your mouth or your eyeballs.
Cosmo
This episode is a public service announcement about washing your paws.
Dr. Universe
It can be treacherous for microbes. They have to compete with other germs. They get jostled off and flushed down the sink when you wash your hands. So sometimes they stick together in slimy groups called biofilms. They ooze out a gluey matrix that makes them harder to wash away.
Cosmo
They just like my belly button so much they never want to leave.
Dr. Universe
That's all for this episode, friends.
Cosmo
Big thanks to Eric Lofgren of Washington State University.
Dr. Universe
As always, if you've got a science question for me, you can submit it at askdruniverse.wsu.edu. 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.
