Bees are dependent on pollen as a protein source and on flower nectar or oils as an energy source. Adult females collect pollen primarily to feed their larvae. The pollen they inevitably lose in going from flower to flower is important to plants because some pollen lands on the pistils (reproductive structures) of other flowers of the same species, resulting in cross-pollination. Bees are, in fact, the most important pollinating insects, and their interdependence with plants makes them an excellent example of the type of symbiosis known as mutualism, an association between unlike organisms that is beneficial to both parties.
Most bees have specialized branched or feathery body hairs that help in the collection of pollen. Female bees, like many other hymenopterans, have a defensive sting. Some bees produce honey from flower nectar. Honey bees and stingless bees commonly hoard large quantities of honey-a characteristic that is exploited by beekeepers, who harvest the honey for human consumption.
Larry Crowhurst/Oxford Scientific Films
Social Structure and Nesting Habits
Bees have diverse nesting and social habits. This diversity has provided scientists with a natural laboratory for the study of evolution and social behavior in insects.
The primitive bees, like their relatives the wasps, are solitary. Each female makes her own burrow, in which she constructs earthen chambers to contain her young. She deposits pollen moistened with nectar or oil into individual cells until enough food has accumulated to provide for the young bee from egg hatching until the larva reaches full size. She then lays an egg on the pollen mass and seals the cell before going on to construct another cell.