Finding scat is one of most obvious ways to tell you have a pest infestation. Mice and rats are the most common animals to leave scat around your home. They will mainly leave their droppings in an enclosed area such as attics, closets, and cupboards. If you have yet to see droppings but you know you have a critter problem, check in these areas for scat. Mice and rat scat is small (around the size of a grain of rice), usually dark brown in color, and have pointed ends.