I was fortunate to observe the initial stages of what I assume was a raid on a bee hive. These hornets often attack hives ambushing returning individual bees or to obtain the honey bee larvae as food for their own larvae. A single scout, sometimes two or three, will cautiously approach the hive, producing pheromones to lead its nest-mates to the hive. This I believe is what I observed. No attack occurred while I was watching but a rotation of three hornets hovered menacingly outside the entrance to the hive which was within a stone wall. The bees were obviously agitated and formed a mass at the hive entrance performing a vibrating dance in unison (some are visible in this image). I felt intimidated not only because I was sitting close to an agitated bee hive but to be in the presence of these awesomely large and majestic hornets presumably plotting the demise of their lesser cousins.
Pu'er, Yunnan, China
For an overload of my Chinese insect and spider images, and non-organic subjects from China, check on my Flickr photostream at http://www.flickr.com/photos/itchydogimages