I have noticed lately that my male Betta fish will flare for no apparent reason as he's swimming in his tank. I can generally calm him down when he sees my face next to the tank, but I don't know what is causing him to flare. I know that stress is bad for Bettas so if something is stressing him out I'd like to fix it. Do Bettas sometimes flare for no reason, or is there likely something in the tank that is frightening him? His tank contains a heater, filter, floating foam flower, fake plants, and a little house, but he doesn't seem particularly scared of any of those.