The incredible mouse living on a volcano

High life: They can cope with any diet as their teeth keep growing. © Marcial Quiroga-Carmona

Scientists have found the world’s highest-dwelling mammal. This mouse is one of the hardiest creatures on the planet, living higher than 22,000 feet and surviving extreme conditions.

What’s happening

Jay Storz wasn’t expecting to find anything alive at the peak of Llullaillaco, the world’s highest dormant volcano in the middle of the Atacama Desert. There is little rain, no vegetation, thin air, and temperatures plunge to -60C. So, he was surprised on arriving, to find a tiny, fluffy mouse.

Find out more

Yellow-rumped leaf-eared mice were already famous with biologists for surviving at extreme altitudes, but this new discovery proves that they can survive in far harsher conditions than anyone thought.

“It’s hard to overstate how hostile it is,” Storz explains. At the freezing peak of the volcano, there is no obvious food source. Biologists suggest that the mice have very slow metabolisms and live off scraps of food that are blown up by the wind.

The mice have also been found thriving at sea level, meaning they can adapt to almost any altitude. Storz thinks this is down to a specially evolved cardiovascular system. The discovery marks the start of a quest to find out more about these creatures.

Are mice the toughest creatures of them all?

Some say…

Yes! These small but mighty creatures survive against all the odds. Their toughness is extraordinary and inspiring. Not only are they record breakers, but they could also be life savers. By studying the way the mice breathe in thin air, scientists hope to learn more about human lung conditions, such as emphysema, so that, one day, they can find better treatments.

Others think…

We don’t know for sure. This discovery may break one record, but there could be endless more species we simply haven’t discovered yet. Many of the world’s highest peaks remain unexplored by biologists. If anything, this expedition shows us that we underestimate the capabilities of lots of animals, and we should not limit our expectations of nature.

You Decide

  1. Do we underestimate nature?


  1. Invent your own record-breaking animal. Draw it and write down its skills.

Some People Say...

“I think nature’s imagination is so much greater than man’s.”

Richard Phillips Feynman, American physicist

What do you think?

Word Watch

In the case of a volcano, when it’s temporarily inactive (asleep).
Atacama Desert
A desert in South America covering land in Chile and Argentina. The Atacama desert is one of the driest places in the world.
Thin air
As altitude increases, the number of gas molecules in the air decreases. Air becomes more dense, with less oxygen, making it more difficult to breathe. Humans suffer from altitude sickness when the air is very thin, but this doesn’t appear to affect the leaf-eared mice!
Distance measurements, usually in the vertical or “up” direction.
More cruel or severe.
Slow metabolisms
Your metabolism is the way your body processes food. A fast metabolism burns calories quickly, meaning more food is necessary. The leaf-eared mice have very slow metabolisms, which means their bodies are particularly good at saving energy from their food and making it last.
Growing healthily.
Cardiovascular system
The system that carries blood and oxygen around the body, having been pumped by the heart.
A disease that affects the lungs. Those suffering from emphysema cannot breathe very well.


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