I have my oscar in a 65 with just gravel and no decor, she has har random freak out moments too. She will swim around violently and slam herself into the lid to get my attention....and its all for food. I have tryed to give her plants, she shreds or kills anything I put in the tank. She has an air stone and likes to hang out in the bubbles, she plays around with a ping pong ball as well.