Bat guano is a common concern for homeowners. Identifying these droppings is important for understanding their source and determining next steps. Knowing the distinct characteristics of bat guano helps differentiate it from other animal droppings.
Identifying Bat Guano
Bat guano appears as small, dark pellets, often resembling grains of rice. These elongated pellets range from about 1/8 to 1/4 inch in length, though some can be up to 1/2 inch. Their color is dark, from black to dark brown, and may have a reddish tint depending on the bat’s diet.
Its texture is a distinguishing characteristic. It is crumbly and easily pulverizes into a powdery dust. This is because bats primarily feed on insects, and their digestive systems leave behind hard, undigested insect exoskeletons. These fragments appear as shiny, glitter-like specks within the guano. Unlike other droppings, bat guano accumulates in piles directly beneath roosting areas, rather than being scattered randomly.
Telling Bat Guano Apart
Differentiating bat guano from the droppings of common household pests, such as mice, rats, and birds, is important for identification. While bat guano and rodent droppings can appear similar in size and color, there are distinct differences in their composition and texture.
Mouse and rat droppings are harder and more uniform in texture compared to bat guano; unlike guano, they do not easily crumble into a powder and lack the shiny insect fragments because rodents consume a different diet, including plant material. Rodent droppings are pointed at one or both ends and are found scattered throughout an area, not in concentrated piles. Bird droppings, by contrast, are easily distinguished by their appearance; they are white and pasty due to uric acid content, appearing splattered, and do not resemble the cylindrical, crumbly pellets of bat guano. Birds excrete uric acid instead of urea, resulting in this white, chalky substance.
What to Do If You Find Bat Guano
If you discover suspected bat guano, taking appropriate safety precautions is important due to potential health risks. Bat guano can harbor a fungus called Histoplasma capsulatum, which can cause a respiratory disease known as histoplasmosis if its spores are inhaled. This risk increases when large accumulations of dried guano are disturbed, causing the microscopic spores to become airborne.
When dealing with guano, wear protective equipment, including gloves and a respirator mask with a HEPA filter, to prevent inhalation of airborne particles. For minor, scattered droppings, misting the area with water before cleanup helps prevent dust from becoming airborne. For significant accumulations, it is recommended to contact wildlife control or pest management professionals. These professionals are equipped to safely remove guano and exclude bats, especially since bats are often protected species, requiring humane handling of their roosts.