Who is that strange creature down the hall? She looks a bit like your little girl, but treat her like one at your own peril! Life with a tween is oh-so-complicated. Our insider's guide dissects their moods and 'tudes, so you can all coexist (somewhat) peacefully for the next few years.

The Pop Queen-Ager

(Hannibus montanibus)

Usually female, although the species is also populated by sensitive males, who invariably star in the school play. Disgust is a common call, which conforms to the Pop Queen-Ager's vocal ability to make every sentence a question: "Um, eww?"

On their iPods: Justin Bieber (though she may pretend not to like him), Miranda Cosgrove, Selena Gomez

Can be found: Lip-synching in front of the mirror (will slam door with a howl of outrage if spotted), feverishly pawing through the latest issue of J-14 magazine, doodling the name Taylor Lautner all over her notebooks.

Plumage: This species tends toward early adoption of makeup and clothes suited for a more mature audience.

May evolve into: Teenager who claims she never, ever listened to Miley Cyrus.