I've had my beta/fighting fish, Sven, for 15 months now, and he has shared a tank with my nerite snails for about 10 of those months. He has never had a problem with them before, but now if one of the nerites is on the side of the glass he flares at it and bobs at it. The snail doesn't seem to notice or care but wondering why this is happening all of a sudden. Any thoughts??