First of all, I didn't know snails had hands. If they have true hands with opposable digits, this is going to really upset the balance of power in the animal kingdom and I'm going out and buying the biggest container of Snarol I can find.
Second, snails' principal predators seem to be crabs. Which led to this bizarre passage:
Alternatively, researchers said crabs might simply not be used to attacking lefties, just as baseball pitchers face fewer left-handed batters.