Early humans lived as hunter-gatherers, following animal migrations and gathering plants for food. Around 13,000 BCE, humans had migrated throughout most of the world. As tools like stone axes and the ability to make fire developed, human culture advanced as well, with the beginnings of language, art, and religion. Around 8,000 BCE, some humans began domesticating plants and animals, leading to the Agricultural Revolution and allowing for permanent settlement as a more reliable food source became available.