Identification Bat droppings, known as guano, are small and dark in coloration. The elongated pellets are crumbly and turn to dust when touched. Often used as fertilizer because of its high nitrogen and phosphorus content, guano can be dangerous when allowed to accumulate in the home. The nutrient-rich droppings cultivate the growth of histoplasmosis fungus, which causes severe respiratory problems in humans. Sign of Infestation Deposits of guano accumulate within walls and attics as well as on the ground and roof tiles. The musty, acrid smell of bat droppings, along with the stains they leave on walls or ceilings, is a sure sign of bat infestations. Due to the hazardous nature of the droppings and the fact that bats are common carriers of the rabies virus, property owners should never attempt to remove bat infestations or clean guano deposits on their own. Contact the wildlife control professionals at Critter Control who expertly remove bats and sanitize affected areas. If you are concerned about a bat problem in your home, bats in attics or would like assistance with sealing bat entry points to your basement or attic, call the experts at Critter Control today at 1-800-CRITTER for professional services! We can help you get rid of bat problems. Call today: 1.800.274.8837.