Mouse Poop – All You Need to Know

Mouse poop, mouse droppings, mouse turds, or mouse sh*t.  Whatever you call it, it’s a sign of something you do not want in your house.  Whether you find the mouse pellets in your bed, kitchen, or a hidden corner of a room you need to start acting fast to get rid of your newfound mouse problem.

Typically one piece of mouse poop equates to an almost definite mouse in your house.  Mouse droppings, along with gnawing marks and odors, are among the biggest signs of a possible mouse infestation in your home.

Warning – Do NOT touch or sniff mouse poop.  Mouse poop may contain extremely harmful bacteria, diseases, and viruses.  It should be cleaned professionally or using the mouse poop cleaning tips below.

Skip Ahead

• What Does Mouse Poop Look Like?
  • Other Possible Poop Types
• Where to Find Mouse Droppings
• Mouse Poop Viruses and Diseases
  • Hantavirus
• How to Clean Mouse Poop
  • Cleaning Mouse Poop from Hard Surfaces
  • Cleaning Mouse Poop on Carpet/Fabric
• Mouse Poop FAQ
  • • What Color is Mouse Poop?
    • What about other Colors like Red or Green Droppings?
    • What Disinfectant Kills Hantavirus?
    • Is Mouse Poop Hard or Soft?
• Mouse Control – Further Reading

What Does Mouse Poop Look Like?

Mouse feces are usually about 1/8 – 1/4 inch in length.  For everyone outside of the United States, Myanmar, and Liberia, that is 3 to 6 mm in length.  They are thin with tapered/pointed ends on one or both sides of the droppings.  With this length and shape, they will resemble pieces of rice that are (usually) brown.

The droppings will usually be brown or black, but the color can vary depending on the food source.  See below for more information about mouse poop color.

Mice poop while walking usually, so you’ll likely notice a scattering of the droppings where you find them.  They can produce anywhere between 50 and 70 droppings on any given day, so it isn’t unlikely that you’ll find several clusters of mouse pellets in different locations.  A full mouse infestation can create thousands of pellets.

Other Possible Poop Types

Tiny brown pellets in your house don’t necessarily mean you have a mouse problem.  There can be any variety of different animal that it came from.  If the description of the droppings didn’t match our identification of mouse poop, see if your findings match any of these:

• Brown Rat Poop: Can be up to 3/4 inch in length and 1/4 inch in thickness.  These are more squared than mouse poop and have blunt ends. They sort of resemble raisins.
• Black or Roof Rat Poop: Usually about 1/2 inch long and a longer sausage-like shape
• Cockroach Poop: Small and granular, resembling coarsely ground pepper.
• Bat Poop/Guano: Found in piles beneath the bat’s resting place or stuck to walls.  Size and shape similar to a long grain of rice.  Often contains undigested insects.
• Squirrel Poop: Very close in resemblance to a mouse turd, but with more rounded edges and a lighter color. If the color starts turning white after a few days it is likely squirrel droppings

Where to Find Mouse Droppings

Mouse excrement is mainly going to be found around their nesting and breeding grounds.  However, they can be found further out often.

Mice tend to defecate around the areas that they have also been destroying.  If you find any gnawed on boxes, wall spaces, or electrical wires then there is likely mouse poop nearby if that was done recently by a mouse.

Mice also don’t tend to venture too far away from walls, so you will mainly find their droppings along the perimeter of a room or inside drawers or cabinet space.

Mouse Poop Viruses and Diseases

Just like any other animal, the fecal matter from mice unfortunately often contains harmful germs.  Viruses, bacteria, and even parasites that can be found in mouse poop and urine.  There is one virus that is the most troublesome called…

Hantavirus

A common virus carried by mouse feces, urine, and saliva is called hantavirus.  Hantavirus is a group of viruses carried by some rodents that can be spread to humans.  It can sometimes develop into a rare disease known as hantavirus pulmonary syndrome (HPS).  HPS can be fatal.

Symptoms of hantavirus include fever, severe muscle aches, and fatigue followed by difficulty breathing.  Humans that breath in the virus from infect rodent’s urine or feces.

How to Clean Mouse Poop

Because there is a good likelihood that mouse droppings can contain harmful germs, it is extremely important that you take every precaution possible when cleaning.  You’ll want to protect yourself while ensuring that the area is completely disinfected.

Do not vacuum mouse poop.  Doing so can send tiny particles in the air that can contain germs like hantavirus.

Cleaning Mouse Poop from Hard Surfaces

1. Open doors and windows and leave the room to allow the area to ventilate for at least a half-hour
2. Always wear latex, rubber, or vinyl gloves
3. Spray the poop with a disinfectant, preferably a mixture of 1 part bleach 10 parts water, and allow it to set in for 5-10 minutes
4. Wipe up the droppings with a paper towel or a rag you’re willing to throw away
5. Throw away the towel in a plastic bag, then throw that bag in another bag that immediately goes outside
6. Disinfect and wipe the area again
7. Clean and disinfect the entire area
   1. Mop the floor with a disposable mop head
   2. Wipe and disinfect the counters, cabinets, and around/under any appliances
8. Throw away the gloves
9. Wash your hands with soap and water
10. Reinspect the area 24 hours later to see if there has been a resurgence of poo

Cleaning Mouse Poop on Carpet/Fabric

1. Open doors and windows and leave the room to allow the area to ventilate for at least a half-hour
2. Always wear latex, rubber, or vinyl gloves
3. Spray the poop with a disinfectant and allow it to set in for 5-10 minutes.  Here you’ll need to use a strong non-bleach disinfectant so you do not ruin your carpeting
4. Scoop up the droppings with a paper towel or a rag you’re willing to throw away
5. Throw away the towel in a plastic bag, then throw that bag in another bag that immediately goes outside
6. Disinfect and wipe the area again
7. Clean and disinfect the entire area
   1. Shampoo and steam clean the carpet
   2. Wipe and disinfect the counters, cabinets, and around/under any appliances
8. Throw away the gloves
9. Wash your hands with soap and water
10. Reinspect the area 24 hours later to see if there has been a resurgence of poo

There are also hantavirus cleaning kits available if you want to be as safe as possible.  Here is a good kit on Amazon.

Mouse Poop FAQ

What Color is Mouse Poop?

Fresh droppings are most often a dark brown or blackish color.  As the feces sit for a few days they will start to dry out, losing the darkness and become a paler brown.

What about other Colors like Red or Green Droppings?

You may however see red mouse poop or green mouse poop around your house.  Occasionally it can actually be pink or blue. Did you happen to leave out any poisons or baits for the mice? 

Many mouse baits and mice poisons come in a bright green or red color.  A mouse digests food rather quickly so the coloring ends up coming out in the stool.

If you see white droppings, it isn’t a mouse.  It’s likely from a squirrel with that coloring.

What Disinfectant Kills Hantavirus?

The best disinfectant to kill hantavirus is a bleach mixture.  You can dilute bleach in a 1:10 bleach to water ratio (1.5 cups of bleach to 1 gallon of water). If you don’t have any chlorine bleach on hand or if you don’t want to bleach any materials, other non-bleach disinfectants will work.  Lysol is known to be effective as well as other disinfectants that state on the label that they kill viruses.

Source – University of New Mexico

Is Mouse Poop Hard or Soft?

Soft mouse poop is a sign of a fresh stool dropping. It begins to harden just a few hours after it is released by a mouse as the moisture leaves it.  After a while it will become dusty and grayish, crumbling very easily.

Mouse Control – Further Reading