Blog · Kitchener
How to clean up mouse droppings safely after a fall mouse problem
Every October the mice come in from the cut fields around Breslau and Doon and through the stone foundations of Kitchener's century homes. Once they are dealt with, somebody has to clean up what they left, and there is a right way to do it.
Last updated September 25, 2026 · Reviewed by the Kitchener Exterminator team
Why droppings are more than a mess
The Region of Waterloo notes that rodents can spread diseases such as salmonellosis, hantavirus and typhoid fever, and that they contaminate food and surfaces through urine, droppings, saliva and fur. The Canadian Centre for Occupational Health and Safety explains that hantavirus is carried in the urine, saliva and droppings of infected deer mice and some other wild rodents, and that people are infected mostly by breathing in particles when that material is disturbed.
Keep the risk in proportion. Public Health Ontario reports no confirmed cases of hantavirus pulmonary syndrome in Ontario in the time the illness has been reportable, which goes back to 2001. The point of a careful cleanup is that it costs little extra effort and removes a risk that dry sweeping creates for no reason.
Step one: stop the mice before you clean
Cleaning a basement while mice are still using it means cleaning it again next week. In Kitchener the entry points follow the housing:
- Century brick homes downtown, in Cedar Hill and around Victoria Park often sit on rubble-stone or early block foundations with mortar gaps, old service penetrations and gaps at the sill.
- 1960s to 80s houses in Stanley Park and Forest Heights tend to lose the battle at the garage door seal, dryer and utility penetrations, and gaps where the siding meets the foundation.
- Farm-edge lots in Breslau and Doon see a sharp jump in pressure when the crops come off, and garages, sheds and woodpiles give mice a staging area next to the house.
Public health guidance for keeping rodents out is consistent: seal openings with wire screening, steel wool, metal flashing or cement; move woodpiles and compost bins away from the building; and keep food and garbage in containers with tight lids. The Region also notes that rodents can gnaw through soft metals, cinder block, plastic and wood, which is why foam and caulk alone do not hold. A mice and rat control visit starts with finding these gaps and ends with a follow-up to confirm activity has stopped.
Step two: the wet-cleaning method
This follows the guidance from the Canadian Centre for Occupational Health and Safety and the Public Health Agency of Canada.
- Air the space out first. Open doors and windows for at least 30 minutes before you start, and keep the space ventilated while you work.
- Put on rubber or plastic gloves. In a confined space such as a crawl space, attic or cold cellar, wear a fit-tested N95 respirator.
- Do not sweep or vacuum. Sweeping and ordinary vacuuming throw particles into the air, which is exactly what the guidance is trying to prevent.
- Soak everything. Spray droppings, urine stains and nesting material with a disinfectant or a mix of 1 part household bleach to 9 parts water until thoroughly wet.
- Wait about 10 minutes. Let the solution sit so it has time to work.
- Wipe up with paper towels or a damp mop. Then disinfect the surface again, including counters, shelves and the floor around the area.
- Double-bag the waste. Put droppings, nesting material, paper towels and dead mice into two plastic bags, seal them, and put them out with the garbage according to local rules.
- Wash the gloves, then your hands. Wash gloved hands in disinfectant and hot soapy water before taking the gloves off, then wash your hands thoroughly with soap and water.
Where to look in a Kitchener house
- The top of the foundation wall and the sill plate, especially behind stored boxes.
- Cold cellars and the space under basement stairs in older homes.
- Behind and under the stove, fridge and dishwasher, and in the cupboard under the sink.
- Insulation in the attic or the joist ends in an unfinished basement ceiling, where nests are common.
- Garages and sheds, particularly bags of birdseed, grass seed and pet food.
Food, clothing and stored items
Throw out any food in packaging that mice have chewed or soiled, and anything stored in cardboard or paper bags in the affected cupboard. Food in sealed glass or metal containers can be kept after the outside is disinfected. Washable fabrics that mice nested in can be laundered in hot water with detergent, while heavily soiled upholstery or stored cardboard boxes are usually better bagged and discarded. Going forward, keep pantry goods, pet food and birdseed in containers with tight-fitting lids, which is one of the simplest ways to make a house less attractive next fall.
Contaminated insulation, heavy nesting in an attic, or droppings throughout a crawl space is a bigger job than a spray bottle and paper towels. The same rules apply, but the scale may call for protective equipment and help.
After the cleanup
Fresh droppings on a cleaned surface are the clearest sign that a gap was missed, which is useful information for the follow-up visit. Keep an eye on the cleaned areas for a few weeks, and keep the traps or stations the technician placed in service until they are cleared. For planning ranges on baiting programs and exclusion sealing, including rubble-stone foundations, see the Kitchener pest control cost guide. To book an inspection, go to the contact page.