Pastoralism is a livestock rearing technique extensively practised by farmers here. They exploit the local natural resources to feed their flocks, thereby shaping the landscapes. It is estimated that this practice started approximately 10,000 years ago. Sheep could be domesticated because they have a natural tendency to herd together. An annual migration called transhumance, which optimises the animals' food intake, involves moving the livestock to high-altitude grazing grounds in the summer when the vegetation is dry lower down in the valley. Grazing helps to keep habitats open, favouring certain animal species, reducing fire risk and maintaining the landscapes, making them a paradise for hikers.