Bird and Bat Droppings Cleanup

Why Droppings Need Care

The main concern with accumulated bird and bat droppings is histoplasmosis. It is caused by a fungus that grows in soil and debris enriched with bird or bat droppings. When that material is disturbed, spores float into the air, and people breathe them in.

Most people who breathe in the spores never get sick, or get a mild illness that passes on its own. For some, it causes flu-like illness with fever, cough, fatigue, chills and chest pain, usually appearing 3 to 17 days after exposure. It can be serious for infants, older adults and people with weakened immune systems.

Other illnesses are linked to droppings too. Pigeon droppings can carry the fungus that causes cryptococcosis, which mainly threatens people with weakened immune systems. Birds can also carry the bacteria that cause psittacosis.

Risk rises with the amount and age of the droppings. A few fresh droppings on a car hood are low risk. Years of buildup under a roost, in an attic, in a barn or chicken coop, or in soil beneath a favorite tree are where spores tend to live. That is where the wet method and good respiratory protection matter most.

Sizing Up the Job

Before you start, decide which kind of job you have.

Look for signs of the animals themselves too. Bat droppings look like small dark pellets that crumble into shiny specks when crushed, and they often pile up below a roost or entry gap. Bird droppings are usually white and chalky, and may come with nesting material and feathers.

If you have a weakened immune system, are pregnant or have lung disease, let someone else do even the small jobs.

The Wet Method for Small Areas

The goal is simple. Keep the dust down and keep it out of your lungs.

• Choose a calm day for outdoor work so wind does not blow dust at you.
• Put on gloves, safety glasses and an N95 respirator at minimum. A half face respirator with P100 filters gives better protection.
• Close nearby windows and turn off window air conditioners and fans that could pull dust inside.
• Mist the droppings with water until they are damp through. Use a fine spray, not a hard jet, which can splash and scatter material.
• Scrape the damp droppings into a heavy plastic bag. Mist again if anything starts to dry.
• Seal the bag and put it in the trash.
• Wash the area with detergent and water, then apply a disinfectant and let it sit for the label contact time.
• Take off gloves and wash your hands and face. Wash clothes separately in hot water.

For droppings on a window air conditioner, unplug the unit first and clean the outside housing and fins gently with the wet method. Keep water away from the electrical parts.

Bats and Rabies Come First

With bats, cleanup is never the first step. Most bats are healthy, but bats are a leading source of rabies in the United States, and their bites can be tiny and easy to miss.

• Never touch a bat with bare hands, alive or dead.
• If anyone was bitten or scratched, or had bat saliva in the eyes, nose, mouth or a wound, wash the area with soap and water and contact a doctor or your health department right away.
• If you find a bat in a room with a sleeping person, a young child, or someone who cannot say for sure whether they had contact, do not release it. Health officials may want it tested. If you can do so safely with thick gloves, trap it under a container and slide cardboard underneath, then call your health department.
• If a bat is in the home and nobody had contact, close interior doors, open a window and let it leave on its own.

When bats are roosting in an attic or walls, hire a wildlife specialist for exclusion before any cleanup. Exclusion uses one-way devices that let bats leave but not return. Many states protect bats and limit exclusion during the summer months when young bats cannot yet fly, since sealing them in can leave pups to die inside. Check with your state wildlife agency.

Attic and Insulation Cleanup

Attics collect droppings for years before anyone notices. Stains on ceilings, a strong ammonia smell, or droppings falling from a vent are common clues.

Attic guano is a professional job for several reasons.

• The amount is usually large, and the dry air of an attic keeps it dusty.
• Droppings sink into loose fill and batt insulation, which cannot be cleaned and must be removed.
• The work needs HEPA vacuums built for insulation removal, sealed bags and air filtration to keep dust out of the living space.
• Heavy urine and guano can stain and weaken drywall ceilings, and the smell can linger in wood.

A good crew seals off attic openings to the house, wears full protective gear, removes contaminated insulation and droppings, cleans and disinfects framing and decking, and treats odor. They then replace insulation once exclusion is complete.

Ask any contractor how they will protect the rooms below, how they will handle disposal, and whether exclusion is finished or will be done first. Cleaning an attic while animals can still get in means paying for the job twice.

Keeping Birds and Bats From Coming Back

Once the area is clean, stop the next buildup.

• Seal entry points after bats have been excluded or birds have left, such as gaps at the roofline, loose vents, chimney tops and holes in soffits. Use hardware cloth, vent screens and chimney caps.
• Install bird spikes, slope covers or netting on ledges, beams and sign tops where pigeons roost.
• Clear old nesting material once it is inactive and legal to remove.
• Do not feed pigeons near your home, and store birdseed and pet food in sealed containers.

Be aware of the law before removing nests. Most native birds and their active nests are protected under the federal Migratory Bird Treaty Act. Pigeons, house sparrows and European starlings are not native and are not protected by it. If you are unsure what species you have, check with your state wildlife agency before disturbing a nest with eggs or young.

Step by Step

1. Identify What You Have

   Decide whether the droppings are from birds or bats, how much there is, and whether animals are still present. Handle any bat situation first.

2. Keep At Risk People Away

   Anyone with a weak immune system, lung disease or pregnancy, and infants and older adults, should stay away from the work area.

3. Put On Your Gear

   Wear gloves, safety glasses and at least an N95 respirator. Use a P100 respirator and coveralls for more than a small spot.

4. Close Openings and Turn Off Fans

   Close nearby windows and turn off window air conditioners and fans so dust does not get pulled indoors.

5. Mist the Droppings

   Spray a fine mist of water until the droppings are damp through. Keep them damp as you work.

6. Scrape and Bag

   Scrape the damp droppings into a heavy plastic bag. Seal it and put it in the trash.

7. Wash and Disinfect

   Clean the surface with detergent and water, then apply an EPA registered disinfectant and leave it wet for the label contact time.

8. Clean Up Yourself

   Remove gloves and coveralls, wash your hands and face, and wash clothing separately in hot water.

9. Block the Next Roost

   Seal gaps, add vent screens or bird deterrents, and have bats excluded by a wildlife specialist before sealing any bat entry.

Mistakes That Make It Worse

• Dry sweeping or using a leaf blower on droppings, which throws spores straight into the air.
• Using a household vacuum on dried droppings. The filter cannot hold fine spores.
• Working without a respirator because the job looks small. A few minutes of dust can be enough.
• Sealing up a bat entry before the bats are out, trapping them inside to die or wander into living spaces.
• Releasing a bat found in a sleeping person’s room before talking to the health department about rabies.

Where You Live Matters