Cheese mites? →
From Wikipedia:
The mites burrow tiny holes in the surface of the cheese and are sometimes intentionally introduced to flavor cheeses like Milbenkäse and aged Mimolette. Cheese that is infested with the mites can have a sweet, minty odor and will appear to be covered in a fine gray dust of the mites, their dander and excrement.
Remind me not to try this kind of cheese. Ever.
