Look closely

What are those?  Are they mouse droppings?  Are they just debris or dirt from the kitchen appliances?  Can you be sure of your answer?
If you have to look twice, then there is cause for concern.  Health inspectors are not infallible, and I would assert that in the history of the NYC Health Dept there has been more than one instance where something that was not "rodent excreta" was called "rodent excreta."
The bottom line is: you cannot be too clean.  You cannot be too diligent.  You cannot work too hard at keeping your restaurant's sanitation as clean as humanly possible.  Why take a chance?
Incidentally, if memory serves, the one on the left was indeed rodent excreta and the one on the right was a food particle.  But since this picture was taken over a year ago, I cannot be certain.