"The bee’s knees" is an idiomatic expression common in many areas of the English speaking world. Typically, the idiom is used to describe and event, object, or person that is considered to be of the highest quality, possessing characteristics that are considered very attractive or set the object apart in some manner. A number of other idioms that include the use of different forms of wildlife also are intended to convey this same state of being outstanding, such as the cat’s pajamas and the eel’s ankle.
The origins of "bee’s knees" appears to have occurred in the early years of the 20th century. Various authors and journalists used the term during the first ten years of the new century to describe items that were somewhat small and insignificant, but unique. The term was sometimes used in satirical pieces as well. By the 1920s, especially in the United States, the idiom had evolved into something entirely different. Beginning with the social elite and gradually gaining traction among people attending college and beyond, "bee’s knees" became a popular way to refer to a popular new dance move, a great new song that was catching a lot of attention, and even to someone who was esteemed to be an ideal potential romantic interest.
During that era, it was not uncommon for radio announcers to use the term when introducing a new recording that was sure to cause a sensation, or for young lovers to proclaim that the boy or girl of their dreams was so outstanding as to be worthy of being referred to as the bee’s knees. As is true of many popular phrases, "bee’s knees" grew in popularity for awhile, then slowly began to lose ground to newer sayings that caught the attention of the public. While the phrase has remained a part of the living language, it is often thought of as being an old-fashioned and fanciful expression that has more to do with the Roaring Twenties that preceded the despair of the Great Depression of the Thirties.
Today, the use of "bee’s knees" usually occurs within the context of stage productions focusing on the era, or when discussing a book written during the early part of the 20th century. While dated, the phrase can still conjure up images of something that is unique and unusually pleasant in some manner, a factor that occasionally prompts one generation or another to make some use of the phrase. Even in limited usage, "bee’s knees" still conveys images of something that is precious, unique and of superior quality.