I've heard a lot of people call Bantams "Banties", perhaps these people got confused and wrote Bandies? But, it is hard to say. There are a lot of black breeds out there. Australorps tend to be the most common of the solid black largefowl sold. But, if it is a bantam it is most likely an Old English (red earlobes), Dutch (white earlobes), or Japanese (short legs and a funny tail set). You will probably have to wait until they are fully feathered, to discover what breed you actually have.