Fresh droppings of rat and mice feces are usually moist, soft, shiny and dark, but in a few days they become dry and hard. Old droppings are dull and grayish and crumble when touched.
The Roof Rat's droppings are up to 1/2 inch long, spindle shaped and curved.
Norway Rat droppings which are about the same length but blunt.
Mouse feces are about 1/8 inch long, and are pointed on both ends.