void on_hunger()
void on_thirst()

Called when a living object's food or drink level drops below 25% during a
food decay tick. The living will pass this event on to their AI modules so
it is possible to instruct mobs to look for food when they realize that they
are hungry, etc...

FOR SCRIPTS: on_hunger
FOR SCRIPTS: on_thirst

Called when you're hungry/thirsty. No parameters.
