What do bat droppings/guano/feces look like?
One way to tell what kind of animal inhabits a space is to examine the droppings. If bats are suspected in an attic or closed space, looking for droppings is a good way to determine if there is an infestation. Bat droppings are called guano and are irregularly shaped and usually contain insect parts. Depending on the type of bat, the guano is generally dried and appears about the size of mouse droppings; however, bat guano is usually found in piles near entrances to colonies, in contrast to mouse droppings, which are found scattered and not in piles. Larger bats will have larger guano with larger insect parts.
The term guano originates with the Inca language and loosely translates to describing droppings of birds found near the sea. Today, the term is used for droppings of sea birds, bats and even coast-dwelling seals. In the Inca civilization, guano was a commodity used like money. Access to guano was restricted and was a prized possession. Since bat guano is so rich in nutrients, it played an important role in agriculture. Guano, from any source, also has played a role in wars and territorial disputes, as nitrates extracted from guano can be used to make explosives of the 19th century type.
Today, bat guano is still used as a fertilizer and can even be purchased online. Many people prefer guano as an organic fertilizer.
Professionally harvested bat guano is usually found in caves where there are huge populations of bats. Guano mining can disrupt the natural balance of animals, as many invertebrates use the guano as a primary food source. Mining the guano also can disrupt the bats that produce the guano, leading to a population reduction of the source bats.