Bees communicate in a hive primarily through the use of pheromones, which are chemical substances produced by the bees. These pheromones help convey information about food sources, the presence of danger, the location of the hive, and the overall health of the colony. Additionally, bees also communicate through physical movements such as the famous waggle dance, which indicates the direction and distance of a food source. Overall, bees use a combination of chemical and physical signals to effectively communicate within the hive.