Which of the following is NOT a common sign of birds in a structure?

Rodent tracks are not a common sign associated with birds in a structure. Instead, these tracks indicate the presence of rodents. When assessing a structure for bird activity, one would typically look for signs directly connected to birds, such as nests, droppings, and the presence of birds themselves flying around.

Nests are often found in eaves, vents, and other sheltered areas where birds may choose to build their homes. Droppings are another clear indicator of bird activity; they are frequently found beneath roosting areas or nests and can accumulate significantly over time. Observing birds flying around the structure further confirms their presence. In contrast, rodent tracks do not signify bird activity, as they are characteristic of a different type of pest issue altogether.