Elephants live in herds of 200 or more animals, led by female elephants. During the day the herd splits into smaller groups to feed and find water. The young are looked after by one or two mothers in 'nursery' groups. Females spend all their lives with the herd but single males sometimes leave and are then known as 'rogues' because they can become very fierce. If an elephant dies the herd mourns and stays by the body for several days, covering it with leaves and earth before they go away.