wool

natural fibres
  As with many discoveries of early man, anthropologists believe the use of wool came out of the challenge to survive. In seeking means of protection and warmth, humans in the Neolithic Age wore animal pelts as clothing. Finding the pelts not only warm and comfortable but also durable, they soon began to develop the basic processes and primitive tools for making wool. By 4000 B.C., Babylonians were wearing clothing of crudely woven fabric. People soon began to develop and maintain herds of wool-bearing animals. The wool of sheep was soon recognized as the most practical to use. Selection for wool type, herd instinct and other economically important features resulted in some 300 different sheep breeds around the world.
Besides sheep, camelids, goats, rabbits, muscox, dogs and cats have fibres that can be used.