In cases such as this, children who have grown up completely isolated from people and society are called feral (wild) children. Because of their lack of outward interaction with others, they have no language skills or knowledge of the outside world.
Feral children may have been severely abused, neglected, or forgotten about before finding themselves alone in the world, which only adds to the challenges of trying to adopt a more normal lifestyle. Kids raised in those conditions typically were left on purpose or ran away to escape.
A young boy named Hadara was one such feral child. He was separated from his parents in the Sahara desert at the age of two. His chances for survival were slim.
Fortunately, a group of ostriches took him in and served as a makeshift family. Fully ten years passed before Hadara was finally rescued at the age of twelve.
In 2000, Hadara's son, Ahmedu, recounted the story of Hadara's younger days. The story was passed on to Monica Zak, a Swedish author, who wrote a book about this case. Although the book is based on many real experiences, it is not completely nonfiction; the author added some of her own fantasy.