SO I just noticed today that my Copperband butterfly went after nori before any of my tangs have. I just got a new rtang yesterday and my other tang has yet to touch nori but I recently just put nori on a clip and my butterfly went straight for it! hopefully he will teach my tangs to eat the nori instead of playing u hit me I hit you next game. Am I the first to have this happen. Constantly nipping at it.