yes .they are not a bad thing. . i let them grow behind the rocks , but the ones i could see on front back and sides of glass i scraped also.

well.........i scraped em off and today i caught the horny little bastards putting more on the glass.......and yes when they are fresh they look just like the pics i found googleing snail larve.....so I'm a proud poppa of about 40 Nassarius snails......they must have done it before as well ...i'm starting to see little tiny {about 1/8 th inch} snails in there at feding time when they come to the surface of the sand and i know all the ones i bought were close to 1/2 inch................so as a sign i guess the tank is matureing nicely if things are breeding,,,,,,right?

Boss