I was cleaning my tank this evening and something odd happened. I had my arm in the tank with the hose sucking up stuff from the bottom when one of my green barbs came up and started nipping at my arm. I chased him away with the hose and thought it was funny and then he came back so I chased him away again. Then some time later he came back again and this time brought one of his tiger barb friends. Both of them started nipping at my arm. Anyway, just thought I would share.