Arctic foxes live in some of the planet's most extreme conditions. An arsenal of cold-conquering adaptations helps them survive temperatures that plummet below -50 degrees Celsius. These include the animal kingdom's best insulating fur and increased blood circulation to the feet which stops the fox's paws freezing to the ice. They range far and wide in the arctic and alpine tundra, but home dens are important and may be used for centuries by subsequent generations. Lemmings are such an important part of their diet that arctic fox populations can be greatly affected by their availability.

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