
Cool Elephant Fact 1: When faced with a leopard call, elephants will not bother moving or changing their activity. When faced with a lion call, they freeze in place, perk up their ears to listen, and move off silently to avoid trouble.
Cool Elephant Fact 2: They do the same with different groups of people.
One key to survival and biological fitness is knowing your enemies -- fleeing costs energy, so animals that know when to run and when to keep feeding will get to feed more than those that are perpetually nervous or interrupted while feeding.