Rats rarely travel more than 200 feet from their nests so if you are looking at some rat poop then there is probably a rat or two hanging out nearby.
Let’s look at a few pictures and talk about whether the droppings you are looking at are from a mouse, rat or squirrel. It is important to know which animal the droppings came from so you can treat the infestation properly.
Rat or Mouse?
The following picture illustrates the difference between droppings from a rat and mouse using a penny as a reference point.
Droppings from the Norway rat (closest to the penny) is the largest of the three and has blunt ends. Droppings from the Roof rat (middle) is a little smaller than the poop from a Norway rat and has tapered ends. Mouse poop (far right) is much, much smaller than rat droppings.
Rat or Squirrel?
Rat droppings and Squirrel droppings are extremely similar in size and shape. The best way to tell the excrement from these animals apart is to look at how it is distributed.
Rats use their poop and urine to mark their territory and indicate breeding status. As a result, rats will poop and pee just about everywhere they travel.
By contrast, squirrels just poop when they need to poop and will often use the same location multiple times.
If you see a large, random scattering of poop along a urine streamed trail then you are looking at rat droppings. If you see a pile of poop then it was a present from your friendly neighborhood squirrel.
Are the droppings fresh or old?
Rats eat a LOT. They need the calories but also must constantly gnaw on materials to keep their teeth trimmed.
Since rats eat so much they also poop a lot (around 40-50 pellets of poop per day).
When you find rat poop it might be left over from an old infestation that has since been eradicated. Fresh rat poop is dark and shiny. Old droppings are grey and dusty.
If the droppings you find are dark and shiny then your rat infestation is currently still a problem.
How to Clean
Please do not approach cleaning up rat droppings like any other cleaning project. These droppings can harbor many dangerous diseases. If the droppings are old, grey and crumbly it is easy to create dust from the poop that can enter your body through your respiratory system.
The minimum protective equipment you need when cleaning is a face mask respirator and rubber gloves. Some people suggest using a HEPA filtered respirator should be used instead of a simple surgical face mask.
Never pick up the droppings with your bare hands.
To minimize the possibility of dust formation and to kill any dangerous viruses it is advised to treat the contaminated area with a mixture of 1 part bleach in 10 parts water using a misting spray bottle. Let the bleach mixture treat the contaminated area for at least 15 minutes before proceeding with cleaning.
Use paper towels to scoop up the rat poop and place the dirty paper towels in a plastic bag for disposal.
Depending upon the contamination you may need to remove and dispose of attic insulation that is soaked with rat urine. Rats use their urine to communicate with other rats. If you leave urine stained materials behind after you have cleaned the rat poop the urine might attract new rats to the location.
It is not advised to use a vacuum cleaner to clean up rat poop as the dust these machines create could be hazardous. If you choose to clean the rat poop with a vacuum cleaner then MAKE SURE the vacuum is equipped with a functional, high quality dust filter. In this case I STRONGLY recommend wearing a HEPA respirator.
For more information about cleaning up after rats including how to decontaminate clothing, rugs, etc read this article from the Center for Disease Control.