because
to be sexy!
Actually Rouge was made to either give Knuckles competition with the master emerald, join the Sonic Team (in episode 78 of Sonic X in English you can see that Rouge might join the Sonic Team to stop EggMan,) be a new bad guy, or to be a neutral character. (Like Charmy, Espio, and Vector.) Or to be a girlfriend to Knuckles or Shadow.
You can create a costume of Rouge the bat.
Rouge is a large fruit bat.
Rouge was a white bat.
Rouge the bat is a Tomboy but she loves pink and purple.
Knuckles is often implied to have a crush on Rouge the Bat.
Noir the bat
Knuckles has a crush on rouge the bat.
http://sonic.wikia.com/wiki/Rouge is an English site about Rouge the Bat and all other things about the Sonic Series
Rouge the Bat's first game was Sonic Adventure 2.
Rouge the bat is a cartoon character. You need to realise that and get over it.
No. Rouge The Bat on Sonic 2 battle does not have any brothers or sisters.
Rouge is a large fruit bat.