I have two Oscars. One is about 2 1/2 inches and the other WAS about 1 1/2 inches. They used to get along great. They would swim around together and play. Friday night we noticed that the bigger Oscar...we call him Dalmer now and you'll find out why....seemed really angry. He was darting around and just looking really angry. Saturday morning, we notice the small one had some scales missing. So did the bigger one, but not as bad. Anyway, we caught him picking at the smaller one. He would nip at him, and he would also swim into him so fast it would knock the smaller one to the gravel. We didn't have another tank to put the smaller one in, so we were going to get a divider temporarily. But he pretty much killed the smaller one before we got the divider. Would any of you know what might have caused the bigger one to suddenly get so angry that he killed the smaller one? I'm SO MAD because the smaller one was so beautiful! Let me know your thoughts.....