I disagree about the "mean" kings being a feeding response. I know the difference. The mean kings I have seen (and owned) we're downright mean. They weren't hungry. Rattling their tails, puffing up, and striking at the glass was not because they were hungry, and bites sustained were not the "grab ahold and don't let go" type of bite. These were defensive bites. The tame kings don't do any of this.