(birds chirping) - [Narrator] Marmots are twice as fat now, as in the spring, are like stags who just lost one fifth of their body mass.
For half a year, these Alpine rodents have stuffed themselves.
(grass ruffling) (wind whooshing) Now it's time to make the den cozy for a long winter underground., To hold out six months underground, you want to comfy home.
In this den, the male prepares the bedding.
His mate supplies the hay.
Out there it's risky.
But as long as the chaffs are watching, one can relax.
(smooth music) (birds chirping) A safe well-furnished den is a marmot's dream but it's not quite there yet.
More padding is wanted.
(marmot snorting) Even when the bed's perfect, with a restless bedfellow, a good rest is hard to get.
Marmots cozy up as families to keep warm.
The temperature inside the den decreases gradually from 60 degrees in autumn to freezing in spring.
The animals also lower their body temperature down to about 40 degrees plus . They survive on their bodies' storage of fat and water.
(wind whooshing) With thick layers of snow and soil on top, the entrance to their extensive den securely blocked, the Marmot is nature's paragon of bunker mentality.
There's not the slightest strife down here no matter how hard the store may blow outside.