"Dido" is an informal or slang term for a mischievous or playful act. "Dido" can also refer to a showy but frivolous object. Both "didos" and "didoes" are acceptable plural forms of dido.
"Dido" is most often used as an informal synonym for prank, but it can also refer to any object for which the name is unknown or as a general term for trinkets or embellishments. In this way it is similar to the more common word "doodad." The etymology of both "dido" and "doodad" is uncertain, but it is possible that "doodad," which first appeared in the 1880s, was a variation of the older word "dido."