Researchers have found a 77,000-year-old plant bedding that has insect-repelling capabilities. This suggests that ancient humans were well aware of the chemical and medicinal properties of some plants.
The bedding consists of thick layers of compacted stems and leaves of sedges and rushes collected from the banks of a nearby river. Though the bedding might have been used for comfort, it would have helped reduce insect-borne disease. The bedding that has been found in a cave in South Africa's KwaZulu Natal province is 50,000 years older than any previous prehistoric beds discovered.
Archaeology professor at the University of the Witwatersrand, Lyn Wadley said, "The leaves contained chemicals that repelled mosquitoes and other insects, so we know that they understood medicinal plants."