Rats and mice are dangerous from a public health standpoint because they can transmit disease through their waste. For that reason, properly removing rodent feces and urine is very important. Rats and mice can also be destructive because they can chew through plastic, wood, soft concrete, glass, rubber, even electrical wire that if it sparks, could start a fire. Some questions answered:

How should residents properly get rid of rat or mouse droppings and other rodent evidence?

The most important thing to remember is to never sweep or vacuum rodent evidence including feces, urine and nesting material. When these substances are swept or vacuumed they can break up, forcing virus particles into the air where they can easily be inhaled, infecting the person doing the cleaning. Hantavirus and Arenavirus are transmitted in this manner.

Steps for proper cleaning:

1. Make a solution of one-part bleach and nine-parts water in a spray bottle or use a general purpose household disinfectant.

2. Wearing rubber or plastic gloves, spray the solution or disinfectant on the dried urine, feces and nesting material until the substances are soaking wet.

3. Let the wet materials soak for five minutes.

4. After five minutes, use a damp paper towel to wipe up urine, droppings and nesting material.

5. Place the paper towel and waste materials in a plastic bag.

6. Then, using the same solution or disinfectant, mop or sponge off the area where the rodent evidence was located.

7. Once finished, put the sponge or mop head into the bag with the rodent evidence.

8. Wash gloved hands with soap and warm water or spray with disinfectant or solution before removing them. Place them in the plastic bag as well.

9. Seal the bag and place in a lidded garbage can.

10. Wash the now un-gloved hands with soap and water.

Once the newly cleaned area is dry (in approximately 30 minutes) it’s ready for reuse.

Would you tell us more about the diseases rats can transmit to humans?

Rats and mice carry two main types of disease in their waste: Salmonellosis and Leptospirosis. Salmonellosis is a type of food poisoning. When a rat or mouse walks through their own droppings or urine, then walks through human food, that transfer of bacteria from the droppings and urine can contaminate the food – making someone sick if they unknowingly eat the contaminated food. Leptosirosis is also a bacterial type of food poisoning that can contaminate food or water in the same method as Salmonellosis.

Rats can also carry a viral disease that is released when dried feces, urine or saliva break up. That virus can be inhaled, causing respiratory illness. That’s why it is so important to carefully clean up any evidence of a rat or mouse.

When do folks typically find evidence of a rat or mouse in their home?

It can happen at any time of year when folks hear scratching, movement or gnawing typically in a cabinet, behind an appliance, in a closet, in a crawlspace, or behind a hot water heater. When the homeowner looks to see what’s making the noise, that’s when they notice evidence of a rat or mouse. Another common time people discover rodent evidence is when they start pulling out the patio furniture, looking in the grill, getting in the garage or shed at the start of spring. At that time, folks are likely to see where the rat or mouse took up residence during the winter.

When people see rat or mouse droppings it’s pretty clear what they are, but dried urine isn’t as easy to detect. What’s a tell-tale sign?

Most of the time there is a spot that looks like a water stain near other evidence or droppings. If there is a large amount, there can also be a
pungent odor. Other evidence that can be found is the rodent’s nesting material which usually includes paper, tissues, insulation, or furniture stuffing.

So, the bottom line is?

Look carefully for evidence of rat droppings, urine and nesting materials and be sure to follow the steps to dispose of it and disinfect the area properly. Most importantly, NEVER sweep or vacuum that evidence because of the risk of transmitting vector-borne disease in the process.