Bumble bee colonies have a relatively primitive social structure. They rarely contain more than few hundred workers and, other than size, there is usually little or no physical distinction between a queen and her workers. Caste determination appears to be based on food supply and the queen’s aggressive behavior. Bumble bees have no system for communicating information about food location to other members of the hive. Novice bees evidently learn to forage efficiently through a process of “trial and error”.
Honey bees include the well-known European honey bee (Apis mellifera) as well as 8 other species of Apis that are native to Europe, Asia, and Africa. These bees usually nest above ground, often inside hollow trees. They construct vertical wax combs with individual hexagonal cells for storing honey and rearing brood. Each hive is “ruled” by a single queen whose only job is to lay eggs. Workers are adult females — daughters of the queen. They perform all housekeeping chores within the hive, search for nectar and pollen, produce wax and honey, feed the young and protect the hive against enemies. Adult workers live for about six weeks (during the summer) but queens may last for several years. During cold winters, the bees cluster together, feeding on stored food reserves and sharing their body heat.
Social caste is determined mostly by the diet an individual bee receives during larval development. Normally, workers feed their larvae royal jelly (a nutrient-rich glandular secretion) for the first few days and then switch to a less-nutritious diet of bee bread (a mixture of honey and pollen). Larvae destined to become queens, however, are reared in special (larger) brood cells and fed a diet of royal jelly throughout the entire duration of larval development. Males (drones) develop from unfertilized eggs. Their only function is to mate with virgin queens.
A queen controls the social organization within her colony by means of a pheromone secreted from her mandibular glands. Workers lick this pheromone from the queen’s body and pass it to nestmates during the exchange of food (trophallaxis). Queen pheromone maintains tranquility within the hive and inhibits ovarian development among workers. When the queen dies (or fails to perform adequately), she is replaced by a new queen reared from within the hive. Each colony, therefore, has the potential to be perennial, that is, to endure beyond the lifespan of the founding queen and her workers. Mature, healthy colonies may grow to include as many as 80,000 workers. However, before they reach this size, most large bee hives will “reproduce” by swarming. This is a process of colony division in which an established queen leaves (absconds) with a large group of workers to establish a new nest site, while a young queen and the remaining workers stay behind to occupy the old nest site.