Nairobi, Nov. 24 -- The girl should be in school, but she is not. In fact, she has never been. She is looking after a flock of six sheep and one goat; the extent of her family's wealth.

In her hand is a long hooked stick that she uses to pull down acacia branches, the only feed available for the animals as the ground is barren. She only speaks Ngi'Turkana, so we need the services of our translator.

"My name is Ayenai," she says. "I come from Ekosowan village and I am the oldest in a family of five children." She does not know exactly how old she is. We soon realise this is common among many children and even adults. "My siblings, three boys and one girl, go to a nearby nursery school, mostly because they can get some food there, but I a...