Well, I have 5 little I guess about 5 inch oscars... I don't know the exact size. Two are always doing "something." I'm not sure if they are trying to pair or kill eachother. They like do this little thing where they like sort of cicle eachother but they end up like... tilted. They also face eachother and like fluff out their gills a little. I don't think they have ever actually bit eachother. But once one bit the other's mouth I guess, but not a lip lock, because that is sort of sideways, this was like one bit the other's lower lip, and it only lasted a second. I'm so confused, I really want to get the other three out so that I can get my pair to start acting as a pair rather than a group, I just don't want to get rid of the other three too early.