In the winter of 2006, millions of bees vanished from their hives without a trace. The epidemic set researchers scrambling to discover why honeybees were dying in record numbers -- and to stop the epidemic in its tracks before it spread further.

The sycomore fig tree and the fig wasp share a curious and important co-dependency.

(Airs Sunday, August 30) It may be one of nature's oddest couples: a tiny wasp and a giant fig tree. The wasp and the fig depend on each other for survival.

In 2006, millions of bees vanished from their hives without a trace. Watch the full episode online now.

Honeybees pollinate about one-third of crop species in the U.S. If bee colonies were so severely affected by CCD that pollination stopped, could we lose these crops forever?

Like ants and termites, common honeybees, which are black with characteristic orange-yellow rings on the abdomen, are social and cooperative insects.

How does such a seemingly passive life form accomplish the complex task of reproduction?