Chimpanzees in Senegal make and sharpen spears with their teeth to go hunting. Like our own ancestors they have learned to use tools to kill their quarry more effectively.

They use their colossal strength to thrust their spears into holes in trees where they suspect nocturnal bushbabies are sleeping.

Anthropologist Jill Pruetz believes she has made a landmark discovery - a species other than humans learning - and passing on - the skills to make a lethal weapon.

The generation of ideas and sharing a skill is a scientific definition of culture.

In another part of Africa a young chimp lowers himself gingerly into a cooling pool and squealing with excitement - in exactly the same way as a human child would. Apes are supposed to be afraid of water but this one is actively using the water as a tool to enjoy a dip.

In controlled laboratory experiments another chimpanzee called Judy quickly learns how to use a complex series of manoeuvres, turning wheels and pulling handles in order, to obtain a piece of fruit from a specially constructed wooden slot machine. But even more remarkably other chimps watch her success and then learn the skill themselves.