from The New Book of Knowledge®
In a field of blooming flowers, bees are a familiar sight buzzing about seeking the rich stores of nectar and pollen held within the flower blossoms. Bees gather the nectar and pollen for food. They turn the nectar into delicious, sweet honey, which people eat. They also produce beeswax, which is used to make candles, crayons, and cosmetics. Many plants would not grow without their help. As bees fly about searching for food, they fertilize plants by spreading pollen from one plant to another. This allows the plants to reproduce.
There are about 20,000 different kinds, or species, of bees. They are found on every continent except Antarctica. There are two general groups of bees: solitary bees, which live alone, and social bees, which live together in large groups called colonies. A colony of bees can contain hundreds, sometimes thousands, of members.
The Body of a Bee
Like all insects, the bee has three body parts: head, thorax, and abdomen. Its body looks fuzzy because it is covered with many fine hairs. Even its antennae, or feelers, are covered with tiny hairs. In addition to a pair of antennae on its head, the bee has five eyes and has chewing and sucking mouthparts. The bee uses its eyes—one pair of large compound eyes and three small eyes—to distinguish colors and different flower shapes. The antennae, or feelers, have sense organs that provide the bee with the senses of touch and smell. Along with the mandibles (jaws) that it uses to cut and chew, the bee has a long tubelike tongue that it uses for sucking.
The thorax of the bee is composed of three segments. The bee has two pairs of wings on its thorax—a large front set and a smaller hind set. The wings, which move up and down and forward and backward, allow the bee to fly forward, backwards, and sideways, and even hover in midair. A pair of legs is attached to each of the thorax segments.
The abdomen of the bee has two very important features. One is a special sac called the honey stomach. In it, the bee carries the nectar it collects. The other is its sting. The sting is attached to the abdomen and is found only on female bees. Some species of bees have better developed stings than others. Within one species, there is also a difference between the sting of the female worker bee and that of the queen bee. The worker bee has a straight sting with hooks. The queen bee has a smooth, curved sting. The worker bee defends its life and home with its sting, while the queen bee only uses its sting to kill other queens.
The honeybee is the most social bee of all. An average honeybee colony has about 30,000 bees, but there may be up to 80,000. The bees live together in their home, called a hive, dividing the labor of the colony. Within the hive, the bees produce wax, which they use to build honeycombs. A honeycomb is made up of a mass of six-sided compartments, or cells.
The colony contains three different kinds of bees: the queen, the drones, and the worker bees. The queen bee is a large female who lays all the eggs in the colony. Although the queen lays eggs from January to November, the majority of eggs are laid between the first warm days of spring and the end of the summer.
At the height of the season, the queen may lay as many as 1,000 to 2,000 eggs a day. Since she lives about five years, she may lay up to 1 million eggs in her lifetime. The queen is the mother of the entire colony, and the whole hive is one big family of bees.
The drones are the males of the colony. They take no part in the work of the hive. They have only one function—to fertilize the eggs of a queen. A typical colony has several hundred drones.
The worker bees are all females. They are smaller in size than the queen. They are able to lay eggs, however, they usually do not lay eggs when the colony has a queen. Worker bees do all the labor in the hive necessary for the maintenance and growth of the colony. Tens of thousands of worker bees live in a typical hive.
Inside the Hive
The beehive is a smoothly run, organized society. Each bee has a job to do. If you watch the entrance of a beehive, you will see the busy traffic of bees coming and going. One after another, bees fly out of the hive. Other bees, heavily loaded with the food needed to supply the colony, land and enter the hive.
Workers called foragers fly out to flowers and collect pollen and nectar. Pollen, necessary for the formation of seeds in plants, is a source of protein, vitamins, and minerals for bees. When the bees who collect pollen groom themselves, they put the pollen grains that cling to the fine hairs of their bodies into special "pollen baskets." These baskets are flattened areas on their hind legs surrounded by long hairs. Nectar is a sweet, sugary liquid. It is 40 to 80 percent water. The bee sucks it into its mouth with its flexible tongue and stores it in its honey stomach.
When a bee returns to the hive, it spits up its load of nectar through its mouth. The nectar is handed over to other worker bees that place it in empty cells. Special chemicals called enzymes are added to the stored nectar. As the nectar dries out, it changes into honey and is a great source of energy for the bees. The nectar gathered by one bee during its entire lifetime is enough to produce about 1.5 ounces (45 grams) of honey.
Duties of a Worker Bee
Some worker bees build the honeycomb. Some clean out empty cells and prepare them for the eggs that the queen will deposit there. Some feed and nurse the growing young. Guard bees stand at the entrance to the hive and protect the hive against enemies, such as wasps, wax moths, and bees from other colonies. Fanning bees ventilate the hive. Still other worker bees take care of the nectar and pollen.
The task of a worker bee depends on its age. For the first three days of its life, the worker cleans a section of the hive called the brood nest, which is the part of the hive where the eggs are laid and the young bees are raised.
During the time the worker bee is preparing the brood nest for new eggs, special glands in its head are developing. Once the glands fully develop, they will secrete a creamy substance called royal jelly. Then the worker becomes a nurse bee, tending the developing larvae (wormlike grubs that hatch from the eggs) and feeding them royal jelly. After several days, the worker stops producing royal jelly and begins to produce wax from glands in its abdomen. At about 12 days, the same bee is a builder of wax cells.
At about 16 days, some workers stop building and start standing guard at the entrance to the hive. There they defend the hive against intruders. Other workers this age receive the nectar and pollen brought by foragers. From the age of 3 weeks until the end of its life, the worker bee shifts to its last and longest job—the collecting of nectar and pollen.
Every bee gathers its own information about the needs of the hive. In any one day it spends part of its time patrolling the hive, inspecting cells and larvae, interacting with other workers, and looking over the building areas and the stores of food. From such inspection tours, new forms of activity start—nursing, building, or cleaning, as each need arises.
In summer when there is a lot of work in the hive, a worker bee may live to only 5 or 6 weeks. During the fall and winter there is less work, so a worker may live several months.
The Mating Flight of the Queen
Each time the hive has a new queen, there is a mating flight. A new queen is needed when the old queen dies, leaves to establish a new hive, or becomes feeble. Special cells in the brood nest house developing queen bees. The first queen to emerge destroys those developing in other cells. If two queens emerge at the same time, they fight until one is killed. An old queen may fight the new queen or leave the hive. Only one queen will emerge from the battles.
When the new queen is about a week old, she leaves the hive for her mating flight. During the flight, she will mate with one or more drones. When they mate, the drone transfers sperm (male sex cells) into the queen's body. The queen stores the sperm until she is ready to lay eggs.
The drones die after mating and the queen returns to the hive. A few days later, the queen starts to move over the honeycombs, looking for empty cells in which to lay her eggs.
From Egg to Adult Bee
If the queen exposes her eggs to the sperm she is storing just before they are laid, the eggs will be fertilized. If she does not, the eggs will be unfertilized. All the unfertilized eggs become males (drones). All the fertilized eggs become females (either egg-laying queens or workers).
The eggs develop into larvae after three days. All the larvae receive the same food, royal jelly, for the first three days. Then some of the larvae receive a mixture of honey and pollen called beebread. The larvae that are fed beebread will become worker bees. Some larvae are selected to be fed only royal jelly. These larvae will develop into queen bees.
The nurse bees carefully tend the larvae, visiting each larva with food nearly 1,300 times a day. At 6 days, the larva starts to spin a cocoon, a shell of silk, inside its wax cell. When the cocoon is completed, the cell is sealed with wax by the worker bees. The larva changes into a pupa within the cocoon. During the pupa stage, the wormlike body of the larva changes into the form of an adult bee. A full-size queen bee emerges from the cell after 16 days. A full-size worker bee makes its way out of its wax cell in 21 days.
Unfertilized eggs go through the same stages as fertilized eggs. They change into larvae and then become pupae. Full-size drones emerge from the cells in 24 days.
With a queen laying 1,500 eggs a day, a new bee emerges almost every minute to take its place in bee society.
How Bees Communicate
Some foragers, acting as "scouts," return from a food hunt and tell other bees from their hive about the food source they have found. The scouts pass on their information by performing a "dance." There are two basic dances that are used to tell the direction and distance from the hive to a source of nectar and pollen: a round dance and a waggle dance. If the returning scouts do a round dance, it means that food is near the hive. The scouts use the waggle dance to describe the exact distance to the food and the direction of the food in relation to the sun. The faster the dances, the closer the food.
In the darkness of the hive, the other worker bees surround the dancing scouts. Using the sense organs on their antennae, the worker bees pick up the flowers' nectar scent clinging to the dancers. The worker bees become excited and start to follow the dancers.
After following the dance, the workers leave the hive and—without the dancing bees to lead them—fly directly to the area of the food source. Once there, the workers search the area for the flowers with the particular scent that clung to the dancing scouts.
The bees form groups just large enough to collect the available food. When the source of the food is plentiful and rich, the worker bees recruited by the scouts also dance on returning to the hive. When the amount of food is reduced, the incoming bees simply deliver the nectar and pollen and do not dance. In this way many bees appear at a good source of food and as the supply wanes, fewer and fewer bees visit those flowers.
Bees also communicate information by the secretions in their bodies. Bees that attend the queen constantly lick a substance from her body and share it with other members of the colony. If the hive loses its queen, the other bees of the colony become aware of her absence in a few hours. They look for her, and if she cannot be found, they immediately set about replacing her with a new queen.
When a hive gets overcrowded, the queen lays fewer and fewer eggs. The worker bees build a new type of cell in the hive. These are much bigger than the other wax cells and are shaped somewhat like peanuts. Inside these special cells, the queen deposits the eggs from which a new queen will emerge. After the larvae develop from the eggs, the cells are covered with wax.
Soon after the cells are covered with wax, the old queen gathers many of the workers and leaves the hive to start a new colony. The departing queen and her group of workers is called a swarm. Their journey from the hive to find a new home is called a swarming. Left behind in the hive are workers that will tend the new queen and developing larvae.
Many scouts search for a new location for the colony. While the scouts search, the swarm gathers around a tree branch or other support. The scouts report back to the swarm using their "dance" language to describe the various locations they have found. The scouts then check out each site. Once one is chosen, the entire swarm travels to the new site.
Bumblebees are another familiar kind of social bee. Their colonies are not as large or complex as those of honeybees, and they do not produce as much honey. Also, the duties of the bumblebee queen are quite different from those of the honeybee queen.
Each spring the bumblebee queen must start a new colony because all of her workers die each year when winter comes. At first, the queen performs the work for the entire hive. She gathers pollen and nectar, builds wax cells, and feeds the young. Not until the larvae become adult workers does the queen have any help with her duties.
The hive thrives for a short time. In the fall, cold weather kills all but the new queens that hatched, and then mated, late in the season. The new queens hibernate and start new hives when the warm weather returns.
Many of the solitary bees have curious habits. Carpenter bees bite tunnels through solid wood. In the tunnels they make a series of cells, one on top of the other and separated by walls of tiny wood chips. Mason bees cement pieces of stone together, forming groups of cells that are attached to cliffs or stone walls. Leaf-cutter bees use their jaws like scissors and snip out pieces of leaves or flowers. They use this plant material to line their nests and make partitions between the cells. Burrowing bees tunnel into the ground.
Most solitary bees live alone. The female solitary bee puts pollen and nectar in the cells of the nest. She lays an egg on each lump of food, seals the cells, and flies away. She usually dies at the end of the summer. When the eggs hatch, the developing young feed on the food left for them. They are completely on their own, having no contact with the mother. When they are adults, male and female mate.
—Millicent E. Selsam