Watching fish behavior is fun, last night I watched two of my SMB come in and cruise around with the BG while I was tossing pellets. The SMB were not interested in the pellets but were looking for small BG to pick out of the crowd, I am pretty sure one of the SMB got a small BG. A little bit later a 16" LMB came in and most of the smaller BG vanished very quickly. An aquarium is very much like a clear water pond.