Honey bee colonies are remarkable for their division of labor among different bee types within each hive. The queen bee — of which there is usually only one, even in a hive with 50,000 bees — is the hiveÃ¯Â¿Â½s only fertile female; she mates, and then lays eggs. Drones are male bees whose only purpose is to mate with the queen. Drones do no other work, and they mate only once before dying; if they donÃ¯Â¿Â½t mate before the beginning of the cold season, they are expelled from the hive. A colony will have only a few thousand drones, and often fewer than 1,000.
Most honey bees are worker bees. These bees are sterile females, and they do all the work of the hive, including tending to the brood, collecting food, feeding and protecting the queen, building cells, and defending the hive.
Worker bees develop from eggs laid by the queen in specially prepared brood cells in a waxen honeycomb made of hexagonal cells. After three days, an egg hatches into a larvae, which is fed by nurse bees — worker bees assigned this special function. These worker bee larvae are first fed royal jelly, a nutritional secretion, and then honey and pollen. (Bee larvae destined to become virgin queens, who will compete with one another to become a new queen if the hiveÃ¯Â¿Â½s current queen no longer produces sufficient eggs, continue to be fed royal jelly.)
The larva is fed for about six days, after which it becomes an inactive pupa. At this point, the cell is capped with beeswax, during which the pupa develops into a worker bee. The fully formed bee emerges on the 20th day, at which point it is able to feed itself, first from stored-up food in the hive and then from flowers and plant life outside of the hive.
Worker bees generally follow a succession of tasks through their short lives. During the first few days after emerging from a brood cell, the worker will clean cells and prepare them for new eggs from the queen. The queen will inspect a brood cell before laying an egg in one; if the cell is unsatisfactory, she will not use the cell, and a worker bee will have to clean it more thoroughly. Young workers also function as nurse bees, feeding royal jelly to young larvae and honey and pollen to more mature larvae.
Young bees are also involved in wax production. Wax is secreted from wax glands, located inside the last four ventral sections of the abdomen, and is used to build honeycombs, either for storage of honey or for use as brood cells. New wax is also needed to repair old cells, and to cap cells (honeycombs as well as brood cells). These Ã¯Â¿Â½wax beesÃ¯Â¿Â½ are also involved in collecting nectar and pollen brought into the hive by foraging bees and storing the honey in honeycombs.
Worker bees in middle age — three to four weeks old — function as guard bees. Entrance guard bees stay at the entry point to the hive, ensuring that all bees attempting to enter the hive in fact belong to that hive; the bees can tell by the odor. Returning bees will generally be forager bees, bringing nectar and pollen back to the hive. Any outsiders trying to gain entry to the hive will be driven off by these guard bees, in conjunction with soldier bees, who also hover near the entrance. Other guards make reconnaissance flights outside the hive and attempt to drive off larger intruders by swarming and stinging.
A worker beeÃ¯Â¿Â½s golden years — the last few weeks of her life — are spent foraging for honey and pollen. Forager bees suck nectar from flowers using a long proboscis and stow the nectar in a special sac called a Ã¯Â¿Â½honey stomach,Ã¯Â¿Â½ where the nectar mixes with enzymes; when a forager returns to the hive, she regurgitates this nectar, and another bee will transfer it to a honeycomb where it is evaporated into honey. Simultaneously, worker bees collect pollen in pollen sacs on their rear legs; this is also brought back to the hive to be used as food, but in the process of collecting nectar and pollen, bees inadvertently transfer pollen from flower to flower. This process of pollination is a critical step in food cycles around the world; a substantial percentage of plant propagation worldwide depends on pollination by bees.
Worker bees carry out many other tasks. They feed drone bees and attend to the queen, grooming and feeding her. They produce honey — storing nectar in honeycomb cells and fanning their wings until the nectar thickens into honey — and pack pollen into special comb cells, where it is mixed with honey to prevent spoilage. They remove dead bees and undeveloped larvae from the hive and dispose of the corpses some distance from the hive. They control the temperature of the hive, clustering together to generate body heat in the colder months and bringing water to the hive in hot months, fanning their wings to cool down the hive by evaporation.
And worker bees can lay eggs. The eggs are unfertilized — all worker bees are sterile — but, through a process known as parthenogenesis (a form of asexual reproduction), these eggs can develop into embryos without needing to be fertilized by a male. Unfertilized eggs, if nurtured, will develop into drone bee larvae. Among some species of honey bees, and particularly among bumblebees, drones are often propagated through this process. Among other species of honey bee, drones usually come from eggs hatched by the queen, and any eggs that happen to be laid by worker bees are destroyed.
Worker bees live a short life — only four or five weeks. If a worker bee happens to be born during the winter, a Ã¯Â¿Â½down timeÃ¯Â¿Â½ for the hive, when most of the bees remain inside the hive living off stored-up food reserves — worker bees may live for several months. In either case, their numbered days are filled with activity.