In general terms, bees are winged, flower-feeding insects that have branched body hairs. Pollen is the main protein source that bees use. They also use oils and flower nectars for energy. The bees collect pollen from different plants. Going from plant to plant they sometimes leave pollen on the plants. The pollen falls on the plants of a different species, which results in cross-pollination. Bees have special bodies that contain branched hair. This type of hair aids the bees in collecting pollen. .
Some bees are able to make honey from the flower nectar. Usually honey bees and sting-less bees create the most honey. There are over 20,000 different species of bees in the world. Lots of them have not been studied or even discovered. Bees can be found across the world with the exception of areas with high altitude or freezing temperatures. The greatest diversity of bees can be found in the American Southwest, Mexico and other warm areas. The length of bees ranges from 2 millimeters to 4 centimeters. Bees are usually black and gray but there are others that are yellow, red, blue and green.
One area of bees that is strongly studied is their social structure and nesting habits. Because they are so diverse, scientists have had a natural laboratory to study these habits. One type of bees are solitary bees. These bees are primitive. The female creates a burrow with chambers for each of her young. She puts pollen moistened with oils into the individual cell chambers until each has enough to provide for the larva that is about to hatch. She puts the egg into the cell and seals it. The larva then grows in the chamber until it has reached full size. .
Another type of bee is the social bee. These bees are communal. There nesting habits are almost identical to the solitary bees with the exception that females of the same generation use the same nest, creating their own cells and chambers for their young.