 It is difficult to pinpoint when exactly the use of cow bells began, but the earliest examples of truly recognizable cow bells date back to the Iron Age.The use of iron bells in sub-Saharan African music and the Niger–Congo area is linked to the early iron-making technology spread during the Bantu migrations.The earliest archaeological evidence of bells dates back to more than 5000 years ago, from the 3rd millennium BC in Neolithic China.