How do you tell the difference? I have a little rubberlip "Mick" he is about 2 inches from tip to tip, not at all very big. He doesn't seem to be growing at all, so I am thinking of adding another. I know that any animal can be territorial, so I don't know which would be better, the same sex or different? That is if I can tell the difference.

Oh guess I should say I have no idea if "Mick" is a boy or girl, just called him that cause of his lips.......Mick Jagger.