Elephants sleep for an average of just 2 hours a day ‚ the least of any mammal.
Sleep is a biological imperative. Some need it more than others, some sleep with half a brain, and some hang upside-down, but one fact rises above all else: All mammals need sleep.
Elephants are the largest land creatures on Earth, but they're also one of the shortest sleepers, requiring just two hours a day to function. Stranger still, these gentle behemoths, renowned for their incredible memories, seem to require little REM sleep, according to studies. Elephants sleep for an average of just 2 hours a day ‚ the least of any mammal.