As with many cartoons that start out with boys as stars, Alvin and the Chipmunks seized on its all-ages popularity by adding girl counterparts... in the middle of its third season. Brittany, Jeanette, and Eleanor--better known as The Chipettes--were brought on board in 1986 to provide a feminine angle to the boys' schemes and adventures. They also served as competitors and love interests for Alvin, Simon, and Theodore, respectively.

Though the girls also sang, danced, and performed for audiences and though they, like the original chipmunks, also had a human caretaker (named Ms. Miller), they weren't exactly replicas of the boys. This is most evident in only one of the three characters: Eleanor. Where Theodore is nervous and timid and bumbling, Eleanor is assured and, though anxious, much better at articulating her concerns and admonitions. Jeanette is also different than Simon, in that she's a bit more batty and discombulated than he and she doesn't serve as the voice of reason as often as her younger sister, Eleanor does.

Despite their cuteness and overall appeal to girl viewers, many who'd been with the show since its inception count the introduction of The Chipettes as a disappointing shift in focus (and even a "jumping the shark" moment). Despite some of the audience tuning out with the increased attention given to competition and banter with the girls, The Chipettes remained part of the TV series until the show's cancellation in 1991. They also served as an integral part of 1987's feature film, The Chipmunk Adventure.