Rat vs Mouse Feces

Rats and mice can be a common pest around the home.  If you have a rodent problem in your house and are not sure whether the invaders are rats or mice, you can examine the feces they leave behind to determine which one is the culprit. 

Rat Droppings

  • are long and spindle-shaped
  • have blunt, round ends

Mouse Droppings

  • measure about 1/8 – 1/4 inch in length
  • have pointed ends

Characteristics of Rat and Mice Droppings

Rat Droppings
  • have a dark color and are soft when fresh.  If the droppings are undisturbed, they soon start to fade in color and become harder.
  • range between ½ – ¾ inch (1.27 – 1.905 cm) in length
  • are about ¼ inch (0.635 cm) thick
  • are long and spindle-shaped
  • have blunt, round ends
Mice Droppings
  • are relatively smaller in comparison to rat droppings
  • measure about 1/8 – 1/4 inch in length
  • have pointed ends

Number of Droppings per Year

An average sized rat leaves approximately 25,000 droppings per year, while an average sized mouse leaves up to 18,000 dropping in a year.  Rats and mice generally leave droppings everywhere they move.

Mouse droppings in house (above)

Diseases Caused by Rat and Mouse Droppings

Rat and mouse droppings carry lots of pathogens that cause human diseases.  Listed below are some of these diseases that are transmitted to humans through rat and mouse droppings.


Salmonellosis arises after an individual has taken water or food contaminated by bacteria of the salmonella species.  It is found all over the world.

Symptoms of Salmonellosis include abdominal cramps, fever, and diarrhea.  Conditions may last up to a week, after which the body recovers. 

Medical assistance is only required when there is a case of life-threatening dehydration.

Hantavirus Pulmonary Syndrome

Hantavirus pulmonary syndrome is a disease that is spread through direct contact with rodent feces or urine.  The virus is also spread through inhalation of dust that has been adulterated with contaminated feces.  In some cases, this infection can be fatal.

Symptoms of Hantavirus pulmonary syndrome include fatigue, fever, and muscle cramps.  In severe cases, patients develop shortness of breath and a continuous cough. 

About 38% of individuals infected by this virus do not survive.

Rat droppings, which can be the source of numerous diseases (above)

Rat Bite Fever

Rat bite fever is a disease that affects many parts of the world.  It is not only transmitted by rats, but can be caused by many other rodents.  Rat bite fever can be contracted from getting a scratch or bite from a rodent, or by eating food that has been contaminated.  The disease can also be transmitted through drinking water that has come into contact with rodent feces.

Symptoms include fever, vomiting, muscle cramps, and headaches.  As the infection grows, a rash appears on the feet and hands.  Swollen joints are also associated with this disease. 

Rat bite fever is treated using antibiotics.  Medical assistance is required, as failure to treat the disease properly leads to fatal consequences. 

Lymphocytic Chorio-Meningitis (LCM)

Lymphocytic Chorio-Meningitis (LCM) is a disease that is associated with rodents like mice and rats.  This disease is usually spread by rodents which are commonly found in the house.  Humans are infected when they come into contact with contaminated saliva, droppings, or rodent nest material.

Symptoms begin with a simple fever and lack of appetite.  As the disease advances headache, vomiting and muscle cramps can be experienced.

Of all the LCM cases reported, less than 1% of victims have died, making this disease relatively non-fatal.

How to Deal With Rat and Mice Feces

The best way to deal with mouse and rat droppings is to create a barrier which prevents these rodents from entering your home.  Common areas where mice and rats enter are through ceilings and basements.  You can prevent these rodents from entering by covering all possible entry points with wire gauze. Mice and rats cannot chew up wire, which makes it an effective barrier against these rodents.  Using rat poison is not a good idea, as it creates lots of problems through decomposing rat carcasses (which can transmit diseases to humans).

Once you have barred rodents from entering your home, the next thing to do is to clean up all areas that have droppings. 

  1. When cleaning areas that have droppings, always make sure to use a gas mask to avoid being infected with particles that have dried and are airborne. 
  2. Use disinfectants to kill bacteria and other germs that may be harbored in places where rodents were frequenting.
  3. After cleaning out all rodent droppings, allow for proper ventilation.  This way you will reduce the chances of being infected by diseases from mouse and rat droppings.