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Sperm whales sometimes sleep in a vertical position: http://en.wikipedia.org/wiki/Sperm_whale#Sleeping http://en.wikipedia.org/wiki/Sperm_whale#Sleeping
by curtis 12y ago
Sperm whales sometimes sleep in a vertical position: http://en.wikipedia.org/wiki/Sperm_whale#Sleeping http://en.wikipedia.org/wiki/Sperm_whale#Sleeping