When sperm whales need a nap, they take a deep breath, dive down about 45 feet and arrange themselves into perfectly-level, vertical patterns. They sleep sound and still for up to two hours at a time between breaths, in pods of 5 or 6 whales, presumably for protection. No one knew whales slept vertically until a 2008 study documented the behavior.

And no one captured really good photography of it in the wild until 2017.

French photographer Stephane Granzotto was documenting sperm whales in the Mediterranean for his book on the creatures when he came across these sleeping whales.

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https://vocal.media/petlife/the-mysterious-sleep-patterns-of-sperm-whales