In a faraway country in a swampy African river, there lived a colony of very happy hippopotamuses. 

Yes, you have got that right hippo-po-ta-mus-es.

 This sounds like a tongue-twister so we shall call them hippos for short.

 Although they all seemed carefree and happy, the happiest of all, was probably little Aurelia. She was like the worker bee, always at hand when someone needed help or was looking for a friend to splash in the muddy-puddle.

However, there was something Aurelia enjoyed most. 

Do you know what was her favourite thing ?

Looking after her little sister Olivia. O yes, she has a sister!

Today is a very special day, Olivia is going to learn hippo's secrets skills, and Aurelia is up to the task.

The first thing Olivia must learn, is how to cool her body against the scorching African sun. There is a secret to it that not everyone knows. Although hippos live in the water, they cannot swim, not even float, imagine!

So now, that you know this, let's see how hippos deal with this problem.

For the first lesson Aurelia took her sister to a shallow water, deep enough that she could be completely submerged while only the top of her head stayed above the water. 

Hippos' eyes, ears, and nostrils are on the top of their heads, so it's not that hard. Hippos can hear, see, and breathe, while most of their body is under water.

After that, Aurelia and Olivia took a break and had lunch, munching on the water plants and splashing warm mud everywhere.

As they continued their lessons, Aurelia showed her sister how to hold her breath under the water while closing her nostrils. 

Then the little hippos proceeded into a deep water and walked along the bottom of the pond using their feet to push themselves off the base. They used this little trick while playing hide and seek under the water.

Finally, the sun started to go down and hippos were going out of the water for their evening meal of fresh grass under the nearby trees. Aurelia and Olivia joined them.