Mine likes to flare at his food before he eats it which i find funny, he flares at the mirror a bit, and each morning after i turn his light on he spends a few minutes flaring at rather large pink eraser that happens to be near his tank. Other than that he flares occasionally when he sees me looking, showing off like dramaqueen said. He does a really cute wiggly dance when he's waiting for food though.
I guess he doesn't appreciate being woken up. lol When I was little, my Mom would come in my room to wake me up for school. She would turn the overhead light on and say "rise and shine!! " It used to irritate the heck out of me! lol
My betta flares at everything. I guess this makes him aggressive. He will flare at a mirror and follow it wherever it goes. He used to attack the red tip of the thermometer in his tank. If you put your face too close to the tank he will flare at humans. He has been known also to flare at a floating pellet just before he destroys it. If i ever have to put my finger in the tank to move something or retrieve an attachment that fell from the side of the tank, he will flare at my fingers.
He is very aggressive and territorial.
I guess this just goes back to the thread about how different betta personalities can be.
Lol, i got him to flare when i put a bigger mirror near him. and he hit the glass once till he realized he couldn't get through it. Then he just puffed up. I was going to get other one to flare, but he is sick and i didn't think that was very nice