Bat droppings, also called guano, sometimes contain microscopic fungi that can cause health problems in humans.

If bats have taken up residence in your home, you will notice their droppings. They are shiny, crumble easily and give off a foul odour. When they dry out, they turn to dust.

The contaminated area must be cleaned to prevent health problems. Take precautions to prevent the dust from droppings from becoming airborne and contaminating other rooms in the house.

Most importantly:

  • Do not sweep up droppings
  • Do not use a household vacuum cleaner to remove droppings and dust from droppings
  • Do not remove droppings without dampening them first

To clean up small quantities of droppings

To clean up small quantities of droppings, follow these steps:

  1. Wear rubber gloves (do not use latex gloves).
  2. Dampen droppings with a water sprayer. Use a low-pressure stream of water.
  3. Clean up the droppings using soapy water and a mop or cloth.
  4. Disinfect affected surfaces with a bleach solution (1 part bleach to 9 parts water). Leave it on for 10 minutes before rinsing and wiping.
  5. Bag and tightly seal insulating wool or any other contaminated material that cannot be disinfected and dispose of it in the regular garbage.
  6. Take off the gloves and put them in the garbage. Wash your hands thoroughly with soap and water.
  7. If possible, put the mop or cloth that was used for cleaning in the garbage. If not, clean it in hot soapy water and then disinfect it with a bleach solution (1 part bleach to 9 parts water). Leave it on for 10 minutes before rinsing and wiping or drying.

To clean up large quantities of droppings or to clean areas that are hard to reach

Sometimes, there is a very large quantity of droppings to clean up or there are many contaminated areas and they are hard to reach.

Hire experts

If there is a large accumulation of droppings or they are hard to reach, it’s best to leave decontamination to the experts. Some pest control professionals offer this service. An experienced pest control professional will have a thorough knowledge of the measures that must be taken and the procedures to follow to remove bat droppings and clean contaminated areas.

To find out the addresses of member pest control professionals who work in your region, contact the Association québécoise de la gestion parasitaire This hyperlink will open in a new window. (in French only) at the following telephone numbers:

  • Montréal region: 514 355-3757
  • Other regions of Québec (toll free): 1 800 663-2730

Do the clean up yourself

If you cannot hire experts, you can clean up areas you can reach by yourself. Make sure you block off access to the contaminated area until it has been cleaned. Make sure you follow the safety measures before, during and after cleaning too.

Personal protective measures

Before starting clean-up and decontamination, make sure you have the proper personal protective equipment:

  • Protective N100 (high efficiency) particulate respirator mask approved by the National Institute for Occupational Safety and Health (NIOSH). These masks filter dust particles and bioaerosols (particles in the air that are composed of or come from living organisms and which can be harmful) that may enter in the lungs. The mask must always fit properly to be effective
  • Safety glasses or a visor
  • Disposable suit (e.g., TyvekTM suit)
  • Disposable shoe coverings or rubber boots
  • Disposable rubber gloves

You can get personal protective equipment in stores that specialize in protective clothing and equipment.

Containment measures

When you have to remove large quantities of droppings, avoid spreading dust from droppings and bioaerosols to the rest of the house by taking the following containing measures:

  • Turn off the forced-air ventilation system and heating system, then seal the mesh over intake and exhaust vents.
  • Contain the area that needs to be decontaminated by sealing all the openings with heavy-duty polyethylene sheeting and duct tape.

Dust control measures during cleaning and decontamination

Reduce the amount of airborne dust from droppings and bioaerosols so that you do not inhale them.

  1. Remove all soiled or contaminated materials. Do not shake them out. Double bag them in heavy-duty plastic bags, that is, put them in a plastic bag lined with a second bag, and dispose of them in the garbage outside.
  2. Dampen dried droppings that have accumulated on all hard permanent surfaces (floor, beams, etc.) with a water sprayer. Make sure you use a low-pressure stream of water.
  3. Pick droppings up with a shovel or dustpan. Double bag them in heavy-duty plastic bags, that is, put them in a plastic bag lined with a second bag, and dispose of them in the garbage outside. If you cannot pick up the droppings by hand, use an industrial vacuum cleaner with a high-efficiency filter. Do not use a household vacuum cleaner.
  4. After removal, disinfect all hard surfaces that were in contact with droppings (floor, beams, etc.) with a bleach solution (1 part bleach to 9 parts water). Leave it on for 30 minutes before rinsing and wiping.

During cleaning and disinfection, control the amount of water used to avoid soaking materials, for this could promote the growth of mould.

Measures after cleaning and decontamination

  1. Take off the disposable suit, shoe coverings and gloves and put them in a plastic bag. Take the protective respirator mask off once all the procedures have been completed.
  2. Put the vacuum cleaner filters in the garbage
  3. Clean the industrial vacuum cleaner and its parts with soapy water. Rinse and then disinfect them with a bleach solution (1 part bleach to 9 parts water).
  4. Take the mask off and put it in the garbage if it is disposable. If not, disinfect it using the method recommended by the manufacturer.

Have the ventilation system cleaned by a specialized firm if you think dust droppings might have entered it.