My new betta, Major Tom, seems to have discovered his very faint reflection in the back of my tank this morning. It has a permanent black backing to it that came with the tank (which I bought off Facebook Marketplace, so you get what you get). He's not hurting himself on the wall because he's not inherently aggressive, but he's been flared for at least 2 hours now. He stopped to eat, but he went right back to it. All my past bettas who have found their reflection in the tank would notice it, flare for less than a minute, and then lose interest. It's amusing now, but any advice if it's still happening by this afternoon? I know it's not good for them to flare TOO much. Thanks!