Snails are probably the only thing that's going to bother with it, and even then, I think by the time a critter did manage to eat it all, it would be gone by it's own.
Usually this will happen in the first month or two of cycling the tank and go away within a week or so. If it's been persisting for over 2 weeks (and you've been scrapping it off the glass), then I'd start to look for the source, rather than try to find something to eat it. Excessive silicates will cause this. What time of gravel/sand are you using? Do you have any rocks, wood or decorations in the tank?
Did you wash the gravel before you put it in?