Quick, what’s the oldest human custom? Picking your teeth. I said custom, not profession.
New Scientist: Grass stalks fit bill for earliest toothpicks
“Teeth from early human fossils as old as 1.8 million years show characteristic grooves that may have been carved by the repeated use of toothpicks. But dental floss didn’t exist and wooden picks don’t leave marks, so the toothpick’s identity was a mystery. But new experimental work shows that grass stalks fit the bill. What’s more, our ancestor’s teeth cleaning habits could be the oldest human custom yet recorded…”