Mouse droppings (mouse feces) are small, dark and pellet shaped between 1/8 to 1/4 inch big. They can bed described as resembling black rice or seeds due to their similarities.
Mice like to stay close to the wall or edges of rooms because it makes them feel secure which is why you will most likely see droppings around perimeters and in other high activity areas.
If you have a mouse infestation its important to have it inspected and treated by a professional that knows what there doing!! Like EcoGuard!
