With that being said the easiest way to distinguish between rat and mouse droppings is to analyze the size of the droppings and their shape.
Roof rat droppings vs mouse droppings.
They may be of different forms or sizes.
Droppings from the norway rat closest to the penny is the largest of the three and has blunt ends.
They are different sizes.
Roof rat droppings are very similar to the house mouse but much thicker.
They are shaped like a sausage curved with ends that are rounded and pointy.
Mouse poop far right is much much smaller than rat droppings.
Rat droppings are bigger than mouse droppings and measure around 3 4 th of an inch in length and around 1 8 th of an inch diametrically.
It s fairly easy to tell the difference between rat and mouse droppings.
Typically the length will still be the same but the thickness will be much greater than the typical field mouse.
In comparison to rat droppings they are small with either one end pointed or both ends pointed.
Medical articles and infographics.
When rat droppings are fresh they are soft and dark and feature a shiny wet surface.
You can see that a house mouse turd is like a small grain of rice even smaller than that often with pointy ends.
Look at the below photos.
A norway rat has capsule shaped feces while a roof rat has spindle shaped droppings and a house mouse has rod shaped excrement.
But a rat pellet is way bigger much fatter with rounded ends.
Rodent feces can carry harmful bacteria diseases and viruses including the hantavirus.
Norway rat poop droppings norway rat poop droppings are even thicker that the roof rats and typically much shorter than field mice and roof rats.