Rodents, Droppings & Hantavirus

Mice and rats leave droppings, urine and nesting material in attics, crawl spaces, sheds, vehicles, storage rooms and buildings that have sat empty. Dust from these materials can carry serious diseases, including hantavirus. Sweeping or vacuuming dry droppings is one of the most common ways workers get exposed.

• Construction
• Home Services
• Maintenance

Diseases rodents can spread

• Hantavirus pulmonary syndrome (HPS): a rare but serious lung disease carried mainly by the deer mouse in North America (and by some other wild rodents). People breathe in tiny particles of dried urine, droppings or saliva stirred up into the air. About 1 in 3 people with HPS die, and there is no specific cure, but early hospital care improves survival.
• Leptospirosis from rat urine in water or soil.
• Salmonellosis from contaminated food and surfaces.
• Lymphocytic choriomeningitis (LCMV) and rat-bite fever.
• Rodents also bring in fleas, ticks and mites. See Biological Hazards.

Where the risk is highest

• Closed, unused spaces such as cabins, sheds, barns, garages, trailers, crawl spaces, attics and storage buildings
• Vehicles and equipment that have been parked for a long time, including air filters and vents
• Demolition and renovation of old buildings, and cleaning out vacant properties
• Rural areas and the West and Southwest of the U.S., though cases occur in many areas
• Work in attics and crawl spaces. See Working in Attics & Crawl Spaces and Confined Spaces.

Symptoms of hantavirus

• Early (1 to 8 weeks after exposure): fever, extreme tiredness, muscle aches (especially in the thighs, hips, back and shoulders), headache, dizziness, chills and sometimes nausea, vomiting or stomach pain. These look like the flu.
• Later (4 to 10 days after the first symptoms): coughing, shortness of breath and chest tightness as the lungs fill with fluid. It can become life-threatening quickly.

Safe cleanup: don’t sweep or vacuum

For small amounts of droppings or a few nests, use wet cleaning:

1. Air out the space. Open doors and windows and leave for about 30 minutes before you start. Don’t enter a closed, dusty space and stir it up.
2. Wear protection. Rubber, latex, vinyl or nitrile gloves. For small cleanups some guidance allows a simple mask, but in enclosed spaces, large infestations or dusty areas, wear a respirator with HEPA filters (N95 or better is the minimum used, with a fit-tested P100 for heavy exposure), and goggles. Follow your employer’s respirator program. See Respiratory Protection.
3. Spray and soak. Wet droppings, urine, nests and dead rodents with a disinfectant, such as a bleach solution (1 part household bleach to 9 parts water, mixed fresh) or an EPA-registered disinfectant, until very wet. Let it soak for 5 minutes or as the label directs.
4. Wipe up with paper towels and put them in a sealed plastic bag. Mop or sponge the area with disinfectant.
5. Disinfect surfaces, tools, countertops and floors that may have been contaminated. Wash fabrics and bedding in hot water.
6. Dispose of everything in sealed bags in the trash, as local rules require. Wash gloved hands with soap and water, then take off the gloves and wash again.

• Never sweep, vacuum or use a leaf blower on droppings or nests. It puts virus into the air.
• Don’t use compressed air or dry dusting.
• Don’t mix bleach with ammonia or other cleaners. Toxic gas can result. See Household Chemicals.
• Don’t touch rodents, dead or alive, with bare hands.

For heavy infestations, large attics or crawl spaces, or commercial buildings, hire a trained cleanup contractor with the proper equipment and protective suits. Contaminated insulation may need to be removed and replaced.

Keep rodents out

• Seal holes larger than about a quarter inch, since mice can squeeze through small gaps. Use steel wool, metal mesh, caulk or sheet metal around pipes, vents, doors, foundations and utility openings.
• Remove food and shelter: store food and trash in sealed containers, clean up crumbs and spills, and remove clutter, brush and woodpiles near buildings.
• Trap rodents with snap traps (set with gloves, bait and a safe placement). Handle trapped rodents carefully using the wet method. Poison baits can harm pets, children and wildlife, so use them only as directed, or hire a pest professional. See Pest Control Technicians.
• Cover vents and chimney openings with screens, and keep doors and gaps closed.

Before you open a closed building or vehicle

• Ventilated for at least 30 minutes; no sweeping or vacuuming
• Gloves, goggles and the right respirator on
• Droppings, nests and surfaces soaked with disinfectant before cleaning
• Waste bagged and disposed of; hands washed; clothing washed
• Entry holes sealed and food and nesting material removed
• I know the symptoms and who to tell if I get sick

Last updated: October 4, 2026