Guano (bat droppings)
There is a popular belief that bat droppings carry a disease that causes death to humans if they come in
contact with it. This is more than a slight exaggeration of the truth!
The disease Histoplasmosis is caused by the spores of
a fungus that grows in bird and bat droppings in enclosed damp areas. In some areas (the southern USA particularly) it occurs in soil,
bird droppings and bat guano, while in others it is unknown. In South Africa it has been identified in the Cape and the Highveld,
while it has not so far been found in the other provinces. The fungal spores are inhaled by people who stir up infected soil or guano.
In most cases Histoplasmosis causes mild flu-like symptoms which clear up after a few days with no continuing problems, but in a very
few people (around one in 100 000 cases) it can develop into a more serious disease. Histoplasmosis has never been described from
dry bat guano in houses; nevertheless, people with asthma or compromised immune systems such as HIV positive persons should avoid
breathing in dust from bat guano and wear a mask when in the roof space.
Bat roost owners who are quite willing to live with
their bats do sometimes complain of dust from the guano falling through the cracks caused by the shrinkage and movement of the cornice
away from the wall. The dust can be vacuumed using the nozzle of a vacuum cleaner and the crack then sealed with acrylic joint sealant,
available hardware stores.
Fertilizer
Bat guano makes an excellent organic fertilizer! One cupful of guano stirred into
a bucket of water and left overnight, then diluted one cupful to another bucket of water, can be used in the same way as any liquid
fertilizer.