The European Starling is an introduced bird species that could almost be considered commensal because of their habits of making a living off humans and our structures.
Their ability to find and detect small openings and to utilize construction gaps on homes and buildings is legendary. Soffit and gable venting, exhaust vents, gutter line gaps are just a few areas on a typical home that are entered by this pest bird.
Large nest size, odors and bird mites are some of the most common issues with Starlings intrusion into homes.
Removal of young birds is away a consideration during nesting cycles, but unless an adult bird is trapped in venting/attic then the flushing of adults, followed by repair of entry points, is the industry standard. Large commercial feed lots may require a trapping program, but residential jobs usually will not. Nest removal is also recommended as some nests will be surprisingly large. Vent pipes for exhaust fans and dryer vents can also become clogged with this nesting.