Animals treat themselves with plants – a behavior humans have observed and imitated for millennia

When a wild orangutan in Sumatra recently suffered a wound to his face, presumably after a fight with another male, he did something that caught the attention of the scientists observing him.

The animal chewed on the leaves of a liana - a plant not normally eaten by monkeys. Over several days, the orangutan carefully applied the sap to its wound and then covered it with a paste of chewed liana. The wound healed with only a faint scar. The tropical plant it selected has antibacterial and antioxidant properties and is known to relieve pain, fever, bleeding and inflammation.

The ...