In a revelation that destroys yet another cherished notion of human uniqueness, wild chimpanzees have been seen hunting bushbabies with spears. It is the first time an animal has been seen using a tool to hunt a vertebrate. Many chimpanzees trim twigs to use for ant-dipping and termite-fishing. But a population of savannah chimps (Pan troglodytes verus) living in the Fongoli area of south-east Senegal have been seen making spears from strong sticks that they sharpen with their teeth. The average spear length is 63 centimetres (25 inches), says Jill Pruetz at Iowa State University in Ames, US, who observed the behaviour. And the method of procuring food with these tools is not simply extractive, as it is when harvesting insects. It is far more aggressive. They use the spears to hunt one of the cutest primates in Africa: bushbabies (Galago senegalensis). Bushbabies are nocturnal and curl up in hollows in trees during the day. If disturbed during their slumbers – if their nest cavity is broken open, for example – they rapidly scamper away. It appears that the chimps have learnt a grizzly method of slowing them down.