We've all seen the cartoons where an elephant shrieks and jumps on a stool when it sees a mouse. (Short pause for Google search of "are elephants afraid of mice?" and the answer seems to be no - but they are frightened by sudden, unexpected movements ... like a mouse running by.) But is there anything that does frighten elephants which could be used by African villagers trying to prevent elephants from munching through their crops. The answer on this one is yes. Bees. Oxford University researchers have shown that 94% of elephants exposed to recordings of angry bees move off, often at a run, as opposed to 20% of elephants who are played "white noise". Of course, this may not be as helpful as it seems. Your average African villager is not going to be able to afford the gear to be able to broadcast bee sounds, and even if they did, elephants are smart* and would soon work out that no real bees were involved. Option B is to have real bees, but this needs careful thought as African bees are apparently very aggressive, and cause painful stings which contain a pheromone that acts like a beacon/invitation for other bees.
* Elephants are apparently smart enough to be able to tell if a human is friend or foe by their scent and the colour of their clothing! They stay away from clothing worn by the Maasi who are known to demonstrate their virility by spearing elephants according to research by St Andrews University - but don't seem to mind clothing worn by Kamba folk who concentrate on agricultural, rather than elephant, pursuits.
Does anyone else think it odd that these two pieces of research into elephants have been conducted by universities in the UK where, to the best of knowledge, elephants are not native.