So i have two bettas in a rectangle tank with a divider in between them. The divider is all black and i cant see through it what-so-ever, and one of the males will flare at the other one, even though he (supposedly) isnt supposed to see through it. The divider goes from side to side so no gaps there, and he will flare as soon as the other male gets close to the divider. Even when hes in the middle of the pure BLACK divider, he still follows him around and attacks the side. Ofcourse, i removed one of them so neither of them get stressed. Am i just missing something, or is something seriously wrong with my betta? Im stumped. (its a ten gallon tank) Im sure theres a simple answer, and im going to feel SO intelligent when i figure it out.