In the arid zones of Africa, there are pastoralists who make a living raising livestock. The arid zones, which have little rainfall, are not suited for agriculture. The rationale for pastoralism in those areas is that people convert natural resources, plants, which are not edible to human beings, into milk and meat by feeding them to animals. In many cases, pastoralists are more or less engaged in agriculture albeit in varying degree. About 15% to 20% of the entire African population, meaning 100 to 150 million people, is considered to rely deeply on pastoralism for their livelihoods.