The bees, as you've probably heard, are dying, in massive numbers. Termed Colony Collapse Disorder, the die-off counts among its causes a parasite aptly named Varroa destructor. A flat, button-shaped, eight-legged critter no more than 2 millimeters long, Varroa mites invade honeybee hives around the world in droves, latch onto their inhabitants, and feed on their tissues, transmitting devastating RNA viruses in the process.