I have raised orphaned squirrels and have seen plenty of squirrel feces. It is about the size of bb's and shrinks as it dries but I have never seen any the size of rice. I also have a covered patio and a yard full of squirrels but none has ever made a deposit on the patio. Is there an odor? I have not noticed much of an odor with squirrel feces. Could it be flying squirrel? They are very small and probably produce a smaller size feces. Roaches leave a black rice size feces and some "outside" roaches are really large.