I just introduced an apple snail to my 6gal tank with a male betta yesterday. So far the snail seems to be under frequent harassment of the betta. Is it possible that the betta eventually grow bored of the snail?
I am not sure because the snail is staying pretty close to inside his shell. I think the betta has left him alone for about an hour now so I'm feeling better about it and the snail is moving around again. I may just give it a day or two for the snail to adjust as well. If it goes downhill I can always remove the snail I guess.
I would suggest to remove the snail if the betta is harassing him constantly. Snails can become traumatized, they will stay inside their shell, and move around without poking their heads out even once due to fear of being attacked.