My neurotic male Veiltail, Swazi, is a tail biter extraordinaire. I think he needs some anti-psychotic medication so he stops mutilating himself.
I had him in a divided 10 gallon and when I added his "roomate" so to say he started this lovely habit. So I switched him with a calmer Betta. My divided 10 gallon is now peaceful.
However, Swazi is in a planted 5 gallon Minibow. The filter is baffled, it's heated to 80*, I do weekly water changes. He's fed 6 out the 7 days the week of good varied food. (Frozen bloodworms, and Attison's/New Life Spectrum/Omega One pellets.)
I play with him daily with the lazer pointer, chasing my finger around, and holding random objects up to his tank. Yes I know I'm weird. :)
He ripped off one of his pectoral fins before I moved him to the new tank. He was always missing half of one his ventral fins. Now he ripped off half of his anal fin, I found a chunk of his tail sitting on his moss ball. I know the keep his water extra clean part, but I need some tips on what to do to discourage this behavior.
I can't leave the lights off. The plants in his tank would not appreciate that. Half his tank is covered with a background to prevent reflection. It's planted so I can't rearrange a whole lot. I try to tire him out by playing with him. What else?