(Intro)

Hi everyone! We're so glad that you've joined us today, because we've made some upgrades to the fort and I've made some upgrades to Squeaks. And, I'm also really excited, because we are going to answer some questions that we've gotten from viewers just like you.

We recently got a big batch of questions from a whole classroom full of SciShow Kids viewers, the Jet class in Ivydale, England. Now, we won't be able to answer all of their questions today, but we're so happy that they sent them. So, thank you! And now, let's open some mail.

Our first question comes from Bea, and she asks, "What are teeth made of?" Bea, that's a great question. Your teeth have three layers, and the cool thing is that the layer on the very outside of your teeth is a material called enamel. And, that's the hardest stuff in your whole body, even harder than your bones. Enamel keeps the inside of your teeth safe and healthy. The next layer under the enamel is dentin. Dentin protects the very center of your tooth, which is the pulp.

The pulp is very sensitive and soft, and is made of little tiny nerves and blood vessels. Now, even though the enamel on your teeth is super hard and can help you chew up lots of apples and carrot sticks, it can still get holes in it. Things like tiny bacteria can build up on your teeth and start to cause little holes to form. And when that happens, these holes are called cavities, and they can really hurt.

So, it's important to take care of your teeth and brush them at least twice a day, because, unlike your bones, your teeth can't fix themselves. And, if you lose your grownup teeth, they won't grow back. So Bea, if you want to learn even more about teeth, you can watch our episodes on what teeth are and why we need to brush them. Thanks for asking.

Alright, our next letter comes from Myla, who asks, "How does it rain?" Another great question, Myla. As you may know, most of the earth is covered with water like lakes and rivers, but mostly huge oceans. And, when that water is warmed up from the sun, it changes into water vapor. Water vapor is simply water in the form of gas. This gas rises into the sky, and it comes to make-- Do you know what it makes?

[Squeaking]

If you guessed clouds, you're right! When the water vapor cools high in the sky, it turns back into tiny droplets of liquid water again. So, the clouds you see in the sky are actually made of countless drops of liquid water, and as more of those water droplets build up in the cloud, the cloud starts to get really soggy and heavy. Finally, the cloud gets so heavy with water that the tiny droplets of water start fall, and that's what you see and feel as rain. Thanks for asking, Myla, and if you want to learn even more about rain and clouds, make sure you watch our episode where does water come from.

Okay, we have one last letter, and it comes from Lana, who asks, "Can you tell us three secrets about Squeaks?" What do you think Squeaks? Do you want to share some things about yourself? 

[Squeaking]

Alright!

[Squeaking]

Squeaks wants me to tell you that he's really smart.

[Squeaking]

And, his favorite band is The Whizpops.

[Squeaking]

And, he loves to play soccer or, as you would say in England, football.

Thank you for sharing, Squeaks. And, thank you to Ms. Cartwright and all the students from Jet class for asking such awesome questions. Do you have any questions that you'd like us to answer about animals or space or maybe just about Squeaks and me? Let us know! Grab a grownup and leave a comment down below or send us an email to kids@SciShow.com. Thanks, and we'll see you next time!