The herd are protecting their calf.
For the musk oxen, it's all for one and one for all.
对于麝牛来说 人人为我 我为人人
It's a struggle for all polar animals
to feed themselves and their families
in the brief Arctic summer.
But there is one tiny creature of the tundra
that has found an astounding solution
to the shortness of the season.
The woolly bear caterpillar.
It's always the first insect to appear after the snow's retreat.
The caterpillar then eats as fast as it can,
and indeed it must,
for this far north, summer only lasts a few weeks.
The days shorten only too soon, but the caterpillar has not yet
got enough reserves to transform itself into a moth.
It can't leave the Arctic, for it can't fly.
So, it settles down beneath a rock.
The sun's warmth rapidly dwindles.
Beneath the rock, the caterpillar is out of the wind,
but the cold penetrates deep into the ground.
Soon, its heart stops beating.
It ceases to breathe and its body starts to freeze.
First, its gut. Then, its blood.