4. Walruses
Walruses take power napping to a whole new level, often sleeping while adrift in chilly Arctic waters. Their impressive tusks come in handy, allowing them to hook onto ice floes or rocky outcrops for stability as they rest.
During long migrations, walruses may spend days at a time in the water, catching sleep in between journeys. This remarkable adaptation helps them survive in some of the planet’s harshest environments. Read more