Zebras are social animals that reside in large groups known as "harems." Mountain and plains zebras live in harems that generally consist of one stallion, six mares and their young. Grevy's zebras only come together as a group for shorter periods of time.
Sometimes, zebra herds congregate together to form a temporary group of around 30 members. Zebras sleep while standing, and when in larger groups, they warn each other of any potential dangers. If a zebra spots a predator, it whinnies or barks loudly to warn other zebras. Zebras are hunted for their skins, and one of the biggest threats to their survival is a loss of natural habitat caused by farming and ranching.