Researchers paid little heed to children in the archaeological record until recently, but in the 1990s more archaeologists began to examine the role of women, leadng some to begin studying other groups, including children. Artefacts and skeletal remains that provide details of child labour from long ago are still relatively scarce, but a surge of interest in the archaeology of childhood is revealing the work that youngsters performed.
     Researchers excavating the ancient salt mines of Hallstatt, Austria, have discovered a child-sized leather cap dated to between 1300 and 1000 BCE, along with very small mining picks. This suggests that children were working in these mines at least two centuries earlier than previously thought. To confirm this, archaeologist Hans Reschreiter at the Natural History Museum of Vienna and his colleagues plan to test human excrement found in the Bronze Age section for sex hormone which younger children would lack.
     When archaeologist Melie Le Roy at the Mediterranean Laboratory of Prehistory in Europe and Africa in Aix-en-Provence analysed a jumble of skeletal remains from prehistoric tombs in France, she found three baby teeth with cylindrical grooves formed when people repeatedly use their teeth for stretching and softening animal tendon or plant material, probably used for sewing or making baskets. The teeth belonged to two children no older than nine. They date to between 3500 and 2100 BCE - the oldest evidence for children engaged in skilled labour. Le Roy is about to start surveying human remains from more than 30 French burial sites from the same time period, and expects to find more evidence of young children at work.
     When archaeologist Steven Dorland at the University of Toronto, Canada, examined ceramic shards from a prehistoric village datng to the 15th century CE in what is now southern Canada, he saw miniscule fingernail marks. The sizes showed that kids aged six or younger were forming clay vessels. In some modern-day communities only pots of a certain quality would be put in the kiln, but at Dorland's site youngsters' misshapen starter pots were also fired.
     Bricks and roof tiles excavated from a Lithuanian castle, dated to between the 13th and 17th centuries CE bear the fingerprints of their young creators. Analysis suggests that children between the ages of eight and thirteen made more than 10 percent of the recovered building materials.

Edited from Nature (18 September 2018)