What is NOT considered evidence of a bat infestation?

The presence of chirping noises from the chimney is not considered direct evidence of a bat infestation. While such sounds may suggest the potential presence of bats, they can also be caused by other animals or factors such as birds or even the acoustics of the structure. In contrast, the other options listed provide more conclusive evidence of a bat infestation.

For instance, the presence of droppings, often referred to as guano, is a strong indicator of bats, as they leave behind feces that can accumulate over time in areas they frequent. Similarly, physical sightings of bats in flight confirm their presence in the vicinity, and the distinctive odor of droppings can indicate a buildup and, thus, the likelihood of resident bats. Therefore, while chirping noises could hint at activity, they do not serve as definitive proof of an infestation.