Enter your email to read this article
Read news on any topic, in one place, from publishers like The Economist, FT, Bloomberg and more.

How does a rhino grow horns, and what was the longest war? Try our kids’ quiz

Illustration of a rhino's head
Illustration: Hennie Haworth/The Guardian
  1. Charlie, 5, asks: how does a rhino grow horns?

    1. It spends an hour every morning pushing the horn out

    2. Horns grow on rhinos the same way that fingernails grow on humans

    3. A rhino is born with full-sized horns, they don’t grow

    4. A rhino’s horn is made of bone that pushes through the skin as it grows older

  2. Lilian, 9, asks: why do humans release endorphins?

    1. To alert your body to hunger

    2. To boost concentration

    3. To cause stress and alert your body to pain

    4. To relieve pain and boost moods

  3. Sam, 7, asks: why do we have leap years?

    1. Because of the time it takes the Earth to orbit the sun

    2. Because the Roman emperor who February was named after wanted an extra day in his month

    3. So that we can all get an extra day of holiday every four years

    4. Because of the time it takes for the moon to orbit the Earth

  4. Alice, 10, asks: what was the longest war?

    1. The hundred years war

    2. The Reconquista

    3. The cold war

    4. The Crusades

  5. Faith, 9, asks: what is the largest flower in the world?

    1. The death flower

    2. The titan flower

    3. The Goliath flower

    4. The corpse flower


1:B - Rhino horns are made of keratin, the same as our nails and hair. A rhino grows its horns in layers of keratin, like we grow our nails!, 2:D - Endorphins are a type of neurotransmitter, a chemical that carries messages. When they are released by our brains, they reduce feelings of pain and increase feelings of happiness., 3:A - Leap years have 366 days instead of 365, with a 29th day in February once every four years. We have them because it actually takes the Earth 365 and a quarter days to orbit the sun. We add all these quarters up into a full day to make sure we don’t slowly go out of sync with the seasons!, 4:B - The so-called Reconquista was a 781-year period of conflict from 711 to 1492, when Christian kingdoms in Spain and Portugal fought with the Muslim Moors for control of the Iberian peninsula., 5:D - The largest individual flower in the world is Rafflesia arnoldii. It is native to Indonesia and it grows to be nearly 1 metre wide! It is nicknamed the corpse flower because it has a strong smell of rotting flesh that attracts insects that pollinate it. Yuck!


  1. 4 and above.

  2. 3 and above.

  3. 2 and above.

  4. 0 and above.

  5. 1 and above.

Molly Oldfield hosts Everything Under the Sun, a weekly podcast answering children’s questions, out now as a book.

Does your child have a question? Submit one here

• This article was amended on 22 November 2022 to clarify the text of the solution to question four.

Related Stories
Everything we know about NASA’s return to the Moon
NASA is set to make another giant leap for mankind as it plans to send more people to the moon – and leave them there.
From analysis to the latest developments in health, read the most diverse news in one place.
On the dark side of the moon
Unmanned Orion is the initial thrust in mankind’s effort to return to the Moon
It's time-out for leap seconds: an expert explains why the tiny clock adjustments will be paused from 2035
Meeting in Versailles, France, on Friday, the Bureau International des Poids et Mesures (BIPM) has called time-out on “leap seconds” – the little jumps occasionally added to clocks running on Coordinated Universal Time (UTC), to keep them in sync with Earth’s rotation.
Curious Kids: how many galaxies are there in the universe?
How many galaxies are there beyond the Milky Way? – Rosella, aged 15, Hong Kong
What is a ‘leap second’ and why are we saying goodbye to them?
It’s time to work out exactly what to do with a problem that has become increasingly urgent, and severe, with the rise of the digital world.
One place to find news on any topic, from hundreds of sites.
In serious times, let the Llandegley International Airport sign be our guide
The end of a long-running spoof signpost to a nonexistent Welsh airport is a sad moment for our determinedly unsilly era