This is one of the most succinct and interesting videos I've ever seen about how bees communicate with each other. Using a series of precise dance moves, they inform their hive mates about the locations of food sources. The vid was made by researchers working with a group at Georgia Tech called the Multi-Agent Robotics and Systems Lab (MARS), where scientists study social insect behavior, and try to apply what they've learned to robotics. Essentially, they'd like to program groups of robots to work together autonomously, but first they need to understand how insects do it.
The researchers found that bees have incredible internal clocks and always know where the sun is, even when they are in the darkened hive. This is important because they use the direction of the sun as part of their "waggle dance" communication, directing their cohort to fly in a direction measured by degrees away from where the sun is currently in the sky. In the hive, however, they are on a vertical surface. So they have to change their communication, substituting the direction "up" for the direction of the sun. Bees also appear to measure distance in energy expended, or possibly numbers of visual cues along a route. This is fascinating stuff, and a good reminder that humans aren't the only creatures around who engage in symbolic communication.