I think I might have some form of pyramellid snails, but I don't have any clams....

[Project Reef]

I have these white unicorn shaped tiny snails. Some species of Pyramellid? I'm not sure.

They only come out at night, hide during the day.

BUT - I do not have any clams right now, nor do I have any snails whatsoever.

If these are truely the "bad" pyramellids then what are they eating? Is it possible to have the "bad" pyramellids in a tank with no clams or snails?