Hello,
Mine no longer extend the "snout" out or the fish will bite at it. Mine move very slowly and they dig into the sand part way but never completely.
They have very attractive shells but they don't seem to clean up the tank much. The other types of snails do more work. I bought 8 have lost 2 and I won't buy anymore of them. I willbe going to get more snails tomorrow, and I have some Fl live sand coming tomorrow as well.