How long are bat droppings toxic?

Bat droppings, or guano, can harbor harmful pathogens, particularly the spores of the fungus that causes histoplasmosis. While the droppings themselves can remain toxic for several months to years if not disturbed, the risk of exposure primarily occurs when they are disturbed and become airborne. Proper precautions should be taken when cleaning up bat guano to minimize the risk of inhalation. Always consult with a professional for safe removal and cleanup.