We don't really need an excuse to feature this adorable photo of twin cubs asleep inside a snow den in Wapusk National Park in Manitoba, Canada. But it just so happens that today is International Polar Bear Day, the perfect day for this shot from the 2007 documentary film 'Earth,' which focuses on wild habitats and creatures across the planet.
Polar bear cubs weigh only about 1 pound at birth. They stay in the den for around two months—by the time they emerge, they weigh as much as 30 pounds.
