bee n.

stinging insect of the genus Apis, living in societies under a queen and producing wax and honey, Old English beo "bee," from Proto-Germanic *bion (source also of Old Norse by, Old High German bia, Middle Dutch bie), from PIE root *bhei- "bee."

Used metaphorically for "busy worker" since 1530s. The sense of "meeting of neighbors to unite their labor for the benefit of one of their number" is by 1769, American English, probably is from comparison to the combined labor and social activity of the insect: Raising-bee (1814) for building construction; quilting bee (1824, see quilt (v.)); logging-bee for a log-rolling; paring-bee for preparing harvested apples; also hanging bee "a lynching"). It was extended to other situations (such as spelling bee, attested by 1809).

To have a bee in (one's) bonnet (1825), of one who is harebrained or has an intense new notion or fancy, is said in Jamieson to be Scottish, perhaps from earlier expressions such as head full of bees (1510s), denoting mad mental activity.