Mesopotamian society originated with the establishment of the first permanent cities between 4000 and 3500 BC. Before then, humans migrated regularly in search of food. This society is regarded for having the first known writing system. Their writing is known as cuneiform. Sticks and bones were used to imprint onto clay tablets. Mesopotamians used a reed to scribble symbols onto moist clay. The clay was then allowed to dry leaving a permanent impression. Primarily, the elect members of society as well as their children were formally taught how to read and write or were able to attend school.