Body Hair
Non-human apes don’t need a tool to carry their infants in part because they have body hair for their infants to cling to but it’s more complicated than simply having body hair and a baby that can grasp it.
Baby Feet
Human feet are unique in the ape family, made for walking instead of grasping. For our babies this means two fewer grasping limbs to help cling to their mother, which means that during the evolution of bipedalism, infants had a harder time hanging on. How did our ancestors survive?
