Wobbly Blue MarbleThe planet, explained for curious children.

Animal · Mongolia, Kazakhstan, Germany

Horse

Equus caballus — the name this animal has in the language scientists everywhere share.

A horse walks on a single toe on each leg, and the wall of the hoof is nothing other than the nail of that toe. The other toes disappeared long ago.

Where does the horse live?

Home: With people on every continent except Antarctica.

In the wild it lives in these countries: Mongolia, Kazakhstan, Germany, the United Kingdom, the United States, Argentina.

The short profile

Fully grown: 142–183 cm at the shoulder, depending on the breed. It weighs about 500 kilograms. On the menu: plants.

The story behind it

Inside a hoof sits the bone that matches the tip of your finger. Everything above it is the equivalent of the rest of a finger, held clear of the ground — so a horse of around five hundred kilograms travels on the same bones a person would use standing on tiptoe. That is why a hoof has to be so hard, and why a lame horse is such a serious problem. The second thing worth knowing is how it sleeps. A horse can doze standing up by locking its legs with a system of tendons and ligaments called the stay apparatus, so it needs almost no muscle effort to stay upright. But deep, dreaming sleep does not work that way: for that a horse has to lie down, and it does so for only an hour or two every few days. A herd takes turns, because someone has to be the one still standing.

Find it on the globe

Horse is there as a tiny animated figure that breathes and looks around. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.

It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.

Questions children ask

Do horses sleep standing up?

They doze standing up, using a system of tendons and ligaments that locks the legs. But for deep, dreaming sleep a horse has to lie down — an hour or two every few days is enough.

What is a hoof made of?

The wall is the same stuff as a fingernail, only far thicker. Inside it is the bone that matches the tip of a finger, plus soft tissue full of blood vessels that cushions every step.

Why is a lame horse so serious?

Because half a tonne rests on four single toes. If one leg fails, the other three have to carry a load they were never built for, and the trouble spreads quickly.

Where these numbers come from

Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.

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