The Upper Palaeolithic period stretches from 35000 to 10000 BC. During this period homo sapiens spread. The techniques for shaping stone improved and new bone, horn and wooden tools were introduced, making life easier for the hunter-gatherers. The first expressions of art emerged. The harsh cold gradually gave way to a more temperate climate. Dwellings were often out in the open or in caves and shelters in strategic sites. Humans hunted deer, goats, wild cattle and rabbits, and they gathered a wide variety of plants and caught freshwater fish.