Bat populations have greatly decreased over the past 50 years. Increased use of chemical pesticides to protect farm crops, gardens, lawns, and forests is a major factor in this decline. Sealing and flooding of old coal mines Forest harvesting of hollow trees Insulating and sealing of homes to reduce energy costs. Bat houses offer an alternative when you force bats out of attics and outbuildings. Houses located on poles or trees will occasionally be used.
Bats can be especially noisy and smelly on hot days.
Other more serious problems can and do develop. Control of these parasites is sometimes necessary. Some people prefer to fumigate the entire space with an aerosol pyrethrum if the area is fairly airtight. Dusting the guano and roost area with boric acid powder or diatomaceous earth can also offer control. Histoplasmosis is a serious disease caused by breathing fungal mold spores that grow in dry guano or soil where the nitrogen-rich guano has dropped.