Bird problems tend to fall into one of four categories: intrusion, nesting transgression, destructive behavior, and fecal damage and contamination.
Intrusion occurs when a bird flies into a house, building, or structure and is unable or unwilling to leave. Herding them out or physical removal is often the solution.
Nesting transgression is when birds nest in inappropriate areas, often obstructing the normal function or aesthetics of a device, mechanism, or construct. This could be a bird nesting in a chimney, in ductwork, in or behind recessed lights, on the exterior of a building, on statues, on monuments, or anyplace that causes problems or issues. Remediation methods vary, but usually include physical removal of the nests and exclusion.