Very often it's not the hermit crabs killing the snails, but cleaning up the dead bodies
I would have to disagree w/ saying "very often". IMO
, at best, it's a 50/50 shot that the snail was actually dead/dieing before the hermit got it. I still have all 3 of the banded trochus snails I had left when I pulled the hermits from my sytem about 4-5 months after getting into the hobby. I'm not a fan of hermit crabs incase you couldn't tell lol- replacing/finding decorative snails is a PITA...