Join Date: Jul 2018
Location: Central Florida
since the weather is warm, I would guess it is droppings from a bug.
here in Florida, I have seen many similar issues even in different colors.
I just wipe clean with a wet cloth and don't worry about it.
the next time I see some, I will take pictures for comparison.
there is no educational alternative to having a front row seat in the School of Hard Knocks.