What is NOT considered evidence of a bat infestation?

The option indicating "chirping noises from the chimney" is not considered evidence of a bat infestation because while bats can emit sounds, the presence of chirping noises alone does not definitively indicate that bats are present. Bats are typically more recognized for their echolocation calls and other sounds related to their activity, rather than continuous chirping. Other potential sources, such as birds or insects, can also create similar sounds that may be misattributed to bats.

In contrast, the other options are clear signs of a bat infestation. Hearing scratching noises generally indicates that bats are active within a space, as they tend to move around at night and may scuffle against walls or surfaces. Seeing bat droppings is a strong indicator since guano accumulates in areas where bats roost. Finally, finding bat carcasses confirms the presence of bats, either from natural causes or due to other environmental factors, and serves as tangible evidence of an infestation.