"Elephants in zoos sleep for four to six hours a day, but in their natural surroundings the elephants rested for only two hours, mainly at night." [1] [1] http

"Elephants in zoos sleep for four to six hours a day, but in their natural surroundings the elephants rested for only two hours, mainly at night." [1] [1] http://www.bbc.com/news/science-environment-39126993 http://www.bbc.com/news/science-environment-39126993