No they wont. I used to have a beautiful 2g hex with ramshorns and betta and had no issues. Then my betta died and when cleaning it found a crack. Luvd that tank....
yup bettas eat them and they reproduce like bunnies! enough will survive his feeding on them to overpopulate your tank.
grab a few that he cannot eat..something that does not fit in his mouth and toss them in
They only eat the little babies that hatch out...witch is not a bad thing with ramshorns
erm i must say though not all bettas have a taste for snails.