My Betta, Sequin, flares at my finger, flares at me from across the room when I stand up, flares at filters (which is why I don't have him in a filtered tank), flares at pieces of paper, and, well, he basically flares at everything. My other males only flare at mirrors or their own reflections. Sir Lefty only flares at other fish, and will NOT flare at mirrors. It's like he knows it's him. Annabeard flares at mirrors, even though she's a girl. Hence the name Annabeard. Her real name is Annabelle, though.
Sequin (m), Shortcake (f), Westley (m), and Sir Righty of Walton (m).