In the stone ages, hunters and gatherers used to follow their prey for hours or days until the animal broke down from exhaustion. Now researchers found that they already knew how to use toxic plants to accelerate the hunt. They analyzed residues on arrowheads that had been excavated in Umhlatuzana Rock Shelter in KwaZulu-Natal, South Africa. The arrow heads were used around 60.000 years ago and carried residues of the neurotoxic plant alkaloids buphanidrine und epibuphanisine. These compounds are present in the exsudate of bulbs from Boophone disticha, an Amaryllidaceae plant indigenous to southern Africa. It is used in traditional medicine as painkiller, but can cause nausea, visual impairment, respiratory paralysis, coma and death when overdosed.