Sumatran orangutans start crafting their engineering skills as infants

The baby primates start early on nest-building techniques — a craft that takes years to hone

large and small orangutan in a tree

Orangutans devote years of practice to nest building, an essential skill for life in the treetops. Sumatran orangutans start learning the skill at as young as 6 months old, a new study finds.

ROMEO GACAD/AFP via Getty Images

At six months old, human infants are still working on sitting up by themselves.