Both Bettas are in a 6 gallon tank with a small school of Rasboras.
The black Plakat, Buster just got moved to his tank last month. It was touch and go as to whether he would eat them or not. I couldn't catch the Rasboras. His tank is too heavily planted. Luckily, a pecking order was established by the next day (can you say: King Buster?) and now it's as if the Rasboras are invisible.
Finn was an adolescent when he joined his Rasboras last year. He actually ate a Rasbora. He felt sick for two days while I fasted him. He had never eaten one again. He does chase them occasionally for fun. They are not afraid of Finn, they just move out of the way.
The key, I think, is that the Rasboras were there first. Except for the one who got eaten (and I suspect it died and got scavenged), the boys have rarely thought of them as food.
I had one Betta in a bowl who flared all the time like Flash. We moved him to a tank and he stopped flaring. We figured out that we must have looked distorted to him, like we were in a fun house mirror. We must have looked scary
Flash and Oliver are gorgeous. I love their color!
Will have to dig up my old flaring photos.. my most flare happy boys know how to move at just the right time to be a blur on my camera >.< I have a flare happy gal who took lessons from my most pro anti photographic male how to be a pain to get in focus.