According to the story from Japan, they are using honeybees to defend against invading crows:
Tokyo is plagued by crows. Not crowds (well, that's debatable) and definitely not cows, but crows. Noisy, aggressive flocks of crows have become such a huge problem that Tokyo city authorities have turned to nature in a desperate effort to combat the ravenous ravens – thousands of stinging bees!
Full Story: http://inventorspot.com/articles/bees_battle_crows_skies_over_tokyo_15980