Tracking milk drinking in the ancient past is not straightforward. For decades, archaeologists have tried to reconstruct the practice by various indirect methods. They have looked at ancient rock art to identify scenes of animals being milked and at animal bones to reconstruct kill-off patterns that might reflect the use of animals for dairying. More recently, they even used scientific methods to detect traces of dairy fats on ancient pots. But none of these methods can say if a specific individual consumed milk.
source https://phys.org/news/2021-01-ancient-proteins-track-early-africa.html
