Bats are often found roosting in the attics and eaves of houses, where they sleep through the day before heading out at night to hunt insects. Bat droppings (AKA guano) is a tell-tale sign that you have bats, but what do they look like, and where are you likely to find bat droppings?
Where do bats live?
Bats can roost in a variety of different places, including sheltered areas around your house. However, it’s not always easy to tell when bats are nearby. These nocturnal creatures are very rarely seen in the day, as they tuck themselves into cracks and crevices to sleep during daylight hours. The natural habitats of bats include caves, rock crevices, mines, under bridges, abandoned buildings, and trees.
Bats that roost in houses may sleep in attics, eaves, guttering, porches, basements, behind broken tiles, and even in the loose mortar between bricks.
If you think you may have bats lodging in your home, one way to be sure is to look out for signs of bat activity in the area, such as droppings. But what do bat droppings look like, and how can you identify them?
What is bat poop called?
Bat poop is called bat guano. This nitrate-rich dung is a highly effective fertilizer and has a long history of use in agriculture.
What do bat droppings look like?
In general, bat droppings:
- Are dark in color
- Are about the size and shape of a grain of cooked rice
- Are found in a specific area (for example, below a roost in the attic or eaves of your house)
- Will crumble into dust when crushed
- May contain little shiny bits of insect fragments that can be seen when the dropping is crushed
Other signs that you may have bats roosting in your attic include:
- A musty, ammonia-like odor
- Oily streaks on walls or ceilings
- Large numbers of discarded moth wings
- Sounds coming from your attic
- Live or dead bats on your property
How to tell bat droppings from mouse droppings
Bat droppings look quite a lot like mouse poop. Both are dark in color and they’re approximately the same size and shape, so how can you tell them apart?
Keep in mind!
The key difference between bat and mouse droppings is texture.
If you’re not too squeamish, pick up some of the droppings you find for closer inspection; mouse poop is often squishy or slimy when fresh, and will harden as it dries. Bat droppings, on the other hand, will crumble into dust if crushed.
Where to look for bat droppings
Guano will accumulate wherever there is a lot of bat activity, so the best place to look for it is in entry and exit points of likely roosting spots. You may see them under the eaves of your house, around porches or windowsills, or in your attic or basement.
Are bat droppings dangerous?
You may have heard that bat poop is toxic but is it dangerous for your health?
Generally, bat poop is not dangerous, but it should still be handled with caution. This is because bat guano encourages the growth of a fungus called Histoplasma capsulatum, which can cause a type of fungal pneumonia called histoplasmosis if inhaled. Histoplasmosis causes symptoms such as:
- Chest pain
- Body aches
In most cases, histoplasmosis only causes mild symptoms or no symptoms at all. However, individuals with weakened immune systems, or those who are exposed to a large amount of the fungus, may develop severe histoplasmosis. Severe histoplasmosis is potentially life-threatening and must be treated with prescription antifungal medication.
How to remove bat droppings
When cleaning up bat droppings, it’s important not to use methods that will raise a lot of dust. If the dust from bat droppings becomes airborne it may be inhaled, which can put you at greater risk of histoplasmosis. The dust may also drift into and contaminate other parts of your house. Therefore, you should avoid sweeping or vacuuming up bat droppings.
To safely remove bat droppings, you should:
- Wear rubber gloves and, preferably, some sort of face covering
- Dampen the droppings first using a low-pressure stream of water
- Use warm, soapy water and a cloth to clean up the droppings
- Place the droppings and any contaminated materials in a tightly sealed bag for disposal (including the gloves and cloth used for cleaning)
- Disinfect affected surfaces
- Wash your hands thoroughly with warm, soapy water
If you have a large quantity of bat poop to clean up, or if the droppings are in a hard-to-reach place, the best course of action is to contact a decontamination expert.
Bats eat nuisance insects, such as mosquitoes, so they’re pretty beneficial to have around. Bats are also shy creatures that are rarely seen in the daytime and will usually avoid humans as much as possible. For these reasons, many people with bats roosting in their homes choose to leave them be. However, large numbers of bats can become a problem, mainly because of the quantities of guano that can accumulate.
Bat removal is notoriously tricky, and the best way to keep bats out of your attic is usually by using bat exclusion techniques. This involves covering up potential entry and exit points to roosting sites using netting and installing one-way exits to keep bats out.
Bat droppings are small, elongated, and dark in color, and look a lot like mouse poop. Unlike mouse droppings, however, bat droppings will disintegrate into dust when crushed. Bat droppings usually accumulate around entry and exit points to bat roosts and may be seen under the eaves of houses, on windowsills, or around porches.
Guano is known to encourage the growth of the fungus that causes histoplasmosis but doesn’t pose a significant risk to human health if only present in small quantities.