(Intro)

Guess what?  It's finally spring where we live.  I love spring because it's finally warm enough to get outside and go on a hike.  Squeaks loves spring because he can play soccer again.  Do you hear that?  That's another thing I love about spring.  The songbirds come back out and start singing.  Hey, Squeaks, do you remember when we learned why birds sing?  

Hi, there!

Squeaks and I were just outside, bird-watching! There are so many different kinds of birds!

Some, like the Northern Cardinal, can sing beautiful songs! Just listen. We call birds that sing like this songbirds.

Lots of birds sing for different reasons. And for songbirds like cardinals, singing is an important way for them to talk to each other. Cardinals will chirp and chitter all year long, but in the spring, they bring out their loudest and prettiest songs.

Why do they sing so much in the spring? They’re getting ready to raise their babies! Like most animals you know, cardinals are usually either a boy, called a male, or a girl, called a female.

They’re pretty easy to tell apart! Male cardinals are bright red, and female cardinals are brown. And both male and female cardinals sing, often for different reasons.

But during the spring, they both sing much more than they usually do. You see, in the springtime, cardinals are getting ready to build a nest, lay eggs, and raise little baby birds! But they can’t do it alone.

They each need to find a mate, another cardinal to help them to feed and protect their babies. A male cardinal wants to become a dad, so when spring comes around, he usually starts looking for a female mate, to have and raise babies with. He’ll start singing, and hope that a female cardinal will hear him.

But showing a female cardinal that he’ll be a good dad takes a lot of work. Female cardinals want to find a mate who is strong and smart, who can find lots of food, and who can protect their babies from other animals that might want to eat them! So the male cardinal has to show that he’s tough enough to help protect his new family.

The best way to do this? Sing loudly! By singing loudly, a male cardinal says, “Here I am!

And I’m not afraid of anything!” He knows that other cardinals can hear him, but there are also other types of animals listening too -- ones like hawks or cats, that might want to eat him! So, his loud song shows that he isn’t even afraid of getting eaten. Male cardinals will even try to sing louder than other males who might be nearby, to prove that they’re the toughest bird around.

Tough enough to be a great dad! Now, to call out to female birds, male cardinals sing a special song called a mating call. This song is different from his normal song; it’s meant just for the girl birds.

A female that’s nearby will want to see which brave male is singing this mating call, so she can decide if she wants to raise her babies with him. If she likes his song, she’ll let him fly over, and they’ll pair up for the spring! Now, it’s not just the males that sing.

Female cardinals will also sing more in the spring, too. Females learn different songs than the males, and scientists are still trying to learn what the females are saying. Maybe someday, we’ll be able to understand everything these birds are saying to each other.

Until then, we’re just lucky to get to enjoy their special springtime songs.

Ooh, it sounds like it's gonna rain, Squeaks.  A nice spring rain is one of my favorite things.  Oh, yeah, I don't blame you, buddy.  I guess I wouldn't like rain very much if I was a robot either.  Well, we don't have to go outside, but let's take a look at the time we learned about why it rains.

Ahh! When you’re thirsty, nothing is better than a nice cool drink of water! Oh, and it looks like my plant could use a drink, too! Did you ever stop to think about where our water comes from? Sure, when you get a drink of water, it might come from a faucet or a bottle... and I give my flower here water from a watering can. But you know what? The water that comes out of the faucet and the watering can may once have been part of a cloud, or a snowflake, or even the ocean! Awesome, right? and it’s because of something called the water cycle.

Now, a cycle is a set of steps that repeat over and over. When you get to the last step in a cycle, you go back to the beginning and go through the steps again. For example, every year there are four seasons: spring, summer, fall and winter.

And when when winter’s over, it’s time for spring again! We go back to the beginning of the cycle. In the water cycle, all of the water on Earth goes through a set of steps that repeat over and over. Let’s start with the step in the water cycle where we open up our umbrellas. [Squeaks squeaks] that’s right, Squeaks! Rain.

Rain is water that falls from the sky. Some rainwater soaks into the ground. But a lot of it flows into little creeks and streams, and then ends up in rivers, lakes, and eventually... the ocean! And then something really interesting happens. Some of this water changes. You might have noticed that after it rains, some water is left on the ground, like in puddles you can jump in. But what happens to all that water? It seems like it’s there one day, but then, after a little while... it’s gone! Well, that water didn’t just disappear.

When the sun comes out and the ground gets warm, water can change into a different form. We call this form water vapor, and water vapor is a gas. The air we breathe, it’s a bunch of different gases mixed together! And like the gases that make up air, you can’t see water vapor gas. When the sun shines on rivers, lakes, and oceans, some of the water changes into water vapor. And then the water vapor goes up high... very high... up into the sky. And it gets pretty cold up there.

So, when the water vapor gets high enough, it starts to get cool. And as water vapor cools down... it changes back into little drops of liquid water. You can actually see water vapor change into water drops right at home! All you need is a mirror or window... and your mouth! Put your face close to the mirror or window, open your mouth nice and wide... and breathe out.

What happens? The glass gets foggy. That’s because there’s water vapor in your warm breath. And when the water vapor in your breath touches the cool glass, it changes into teeny tiny droplets. A lot of the droplets together make the glass look cloudy.

And up in the sky, a lot of water droplets together make... clouds! When there’s a lot of water in a cloud, the cloud starts to get darker. White fluffy clouds start to turn gray. And as the clouds get grayer, the water in them gets heavier. When the water gets too heavy, it falls, right back out of the clouds, as rain. And rain is where we started in the cycle! We made it all the way back to the beginning! Now the water cycle can start over again.

All the water on our great big Earth goes through this same cycle, over and over. Its falls the ground as rain or snow. And soon that water ends up in a river, lake, or ocean. From there, it heats up and turns into vapor. And when the vapor rises into the sky and cools off, it comes right back down!

So the water that you drink, and the water that’s in my watering can right now, might once have been part of a raindrop that fell into the ocean on the other side of the world! Think about that next time you take a drink!

Now that the weather is warmer, we can't wait to start planting our garden.  We grow carrots, lettuce, all kinds of flowers, and they all start from tiny little seeds.  You're right, Squeaks, it is pretty amazing.

Oh hey guys. Squeaks and I are checking out our plants and they look great! It's almost hard to believe that these beautiful flowers and plants came from the teeny tiny seeds we put in the pots just a few weeks ago. You might be familiar with the little packets of seeds that you use to grow flowers or vegetables in your garden, or maybe the sunflower seeds that you find in your snack mix, but did you know that popcorn kernels, beans, peas, acorns, and rice are also seeds? One of our friends, five year old Dimitri, wrote in to ask us, "How does a seed grow into a plant?" Thanks for asking Dimitri.

First of all, seeds come in lots of different shapes and sizes, but they're all made of three parts: an outer shell called the seed coat, a tiny baby plant that's inside the seed called the embryo, and some plant food for the embryo called endosperm. The seed coat has an important job - it covers the entire seed, protecting the little baby plant inside and keeping it from drying out. The seed coat also has super sensing powers - it has special chemicals in it that can tell when the seed is in the right place to start growing. For example, the sunflower seeds and the pumpkin seeds in your trail mix sense that it's not safe to grow. After all, seeds can't grow when they're surrounded by raisins and chocolate chips. So while the seeds are in a bag or in your hand it's like they're asleep. The seeds are still alive, but they're dormant or inactive. Some seeds can stay like this for hundreds or even thousands of years.

<Squeaks squeaks>

Great question Squeaks! To get started every seed needs water, the right temperature, and the right amount of light. Once the seed has these three things, like when it's planted in some nice wet soil, the embryo, or baby plant, gives the signal to start growing. For plants, this growing process is called germination. First, the seed coat lets some water through to the embryo, but the water needs more then just water if it's going to grow. Good thing there's a whole bunch of plant food right there inside the seed. Until the plant can make it's own food from sunlight, which it will need leaves to do, it relies on the endosperm for energy. It's like the little baby plant has it's own backpack of snacks.

So the embryo keeps growing and taking in more water until the seed coat cracks open and the embryo kicks out a kind of a foot - but not at all like my foot. The first part of the plant to come out of the seed is the root. The root always grows downward, no matter what way the seed is planted. A seed can actually tell which way is up and which way is down. So the root pushes down deeper and deeper into the soil looking for more and more water to feed the baby plant. Once the plant is all grown up those deep roots will have another job - they'll help keep the plant from falling over or blowing away in the wind. But soon after the first baby root finds it's way to the dirt another part of the seed pops out - this time in the opposite direction.

A shoot, which has the stem of the plant and a few leaves pushes it's way up towards the sunlight. Once the shoot breaks through the soil to the open air above we say that it's sprouted. Now the plant doesn't need endosperm anymore because it can make it's own food from sunlight. With enough water and sunlight and the right temperature the young plant will continue to grow, growing bigger and getting more leaves until it's an adult plant and it can produce seeds of it's own.

One more thing that's really cool and kind of gross about spring is that all kinds of bugs start showing up.  Pretty much anywhere you look, you can find bees, spiders, centipedes, worms, and lots more.  In fact, Squeaks and I went on a bug safari in our backyard not too long ago.  Check it out.

We’re looking around the yard to see what kinds of things we can find. And I know of a great place to find lots of cool stuff, stuff that you might not otherwise see... under rocks!

Now, the underside of a rock might not seem like a place where you and I would want to live. It’s dark, it’s kind of chilly, and it’s usually pretty damp. But it’s the perfect place to look for insects, spiders, slugs, and other animals! For lots of reasons!

For one thing, there’s lots to eat under there! Rotting leaves, old grass, and other kinds of plants make good food for small animals like insects. And then other creatures, like spiders, eat insects! So there’s usually plenty of food to go around.

Another reason that life's so good under a rock? You and I might like sunshine, but lots of other animals like it dark and damp. The moisture under rocks keeps animals like worms from drying out. And the darkness makes it easier for them to hide from hungry predators. So, if you want to find some cool creepy-crawlies, look no further than your nearest rock!

But here are a couple of rock-flipping tips. First, look for rocks that are in a quiet, out of the way place. You also want them to be kind of big, but not too big... otherwise you won’t be able to turn them over! So, look for rocks that are about the size of a grown up’s shoe. It’s also better to look under rocks that have dirt or grass under them, instead of cement or other rocks. And be careful when you turn it over! If you’re lucky enough to find something under there, you can look at it, but don’t touch them.

Okay, ready? Let’s see what we can find under this one! Whoa, look at all the living things! Let’s write down what we see before they all have a chance to run and hide! Okay, the first thing I see are insects. Lots of them.

There are lots of kinds of insects that live under rocks. But some of the most common ones are crickets, ants, and beetles. One of my favorite things about insects is that they can change into different forms as they grow up. An insect’s life begins as an egg. And sometimes an insect egg hatches into what are called larva. A caterpillar is a kind of insect larva.

Then the larvae goes through some really big changes, and becomes an adult! Oh, and look! I see some beetle eggs under our rock, too! They look a little like rice. And you see those things there? Those things that look like short, squishy, worms? Those really aren’t worms at all. They’re grubs! A grub is a beetle larva. Just like a caterpillar will someday be a moth or a butterfly... this grub will someday be a beetle. And I can see some adult beetles, too.

I also see some spiders. They look and act kind of like insects, but spiders have eight legs, and only two body segments. And spider eggs don’t hatch into larvae... they hatch into tiny spiders called spiderlings.

Ooh, look! There are some slimy-looking things stuck to the bottom of the rock. These definitely aren’t insects, or spiders! They’re animals, called slugs. A slug looks like a snail without a shell. They don’t have any legs. Instead, slugs have a huge muscle called the foot that helps them move. And slugs make slime, lots of it. In fact, slugs leave a trail of slime behind them wherever they go. This slime helps keep the slug from getting too dry.

Wow, there were a lot of things under that rock! Spiders, insects, and slugs are just a few of the things that you might find under a rock. If you turn over a rock in your neighborhood, you might find centipedes, snails, or even salamanders. Now that you know what to expect when you turn over a rock, are you ready to explore? I am... c’mon Squeaks, let’s go find another rock

Alright, Squeaks, we can go out to play soon, but there's one more spring activity that we need to do first: spring cleaning.  The Fort is a mess.  It's okay, buddy, we'll be done before you know it, and then we can go play on the playground.  What are your favorite things about spring?  We'd love to hear about them, so grab a grownup and leave a comment down below or send us an email to kids@scishow.com.  

Alright, Squeaks, let's get to sweeping.

(Endscreen)