Do elephants sleep?

Yes they do.

But wild African elephants sleep for the shortest time of any mammal, according to a study.

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. Sometimes they stay awake for several days. During this time, they might travel long distances, perhaps to escape lions or poachers.

Yes, elephants need sleep.