Something is killing off up to half of America's bees--terrible news for bees and the vegetation that depends on them for pollination. Fewer bees not only means less honey, it means less food. Researchers at Harvard are working on a partial solution -- tiny drones the size of bees (not to be confused with drone bees, the mostly useless males of a bee colony).
The robo-bees aren't ready for prime time yet. Because they're so tiny, they can't fit a battery pack for power. The bees will also need some sort of computer so they can guide themselves in flight. Right now, there's no onboard guidance mechanism--again, they just don't have the real estate.