Marmots are sociable animals that live in family groups of up to twenty individuals. They dig a system of tunnels and burrows under the meadow, with separate chambers for sleeping, storing food and sheltering from bad weather. The main chamber where the family spends winter is lined with dry grass to keep it warm. From above ground, you can often spot the entrances to their burrows as neat round holes among the rocks.
One of the most remarkable things about alpine marmots is their winter sleep. When autumn arrives and temperatures drop, the whole family group bundles together deep in their burrow and enters a deep sleep called hibernation that lasts for six or seven months. During hibernation, their heart rate drops from around 120 beats per minute to just three or four beats per minute, and their body temperature falls close to freezing. They live off the fat they built up by eating all summer.
In summer, marmots are busy from morning to late afternoon, mostly eating — grasses, roots, flowers, berries and seeds. They need to eat as much as possible to build up enough body fat to survive hibernation. You can often spot them sitting upright on a boulder at the edge of their meadow, looking out for eagles and chamois. When danger is near, the marmot on lookout sends a piercing whistle, and the whole colony dives for their burrows in seconds.