Majority of damage that starlings cause is in the spring/summer when they are nesting to lay their eggs. They use Bathroom and Dryer Vents a lot to build nest inside which stop the ability for the vent to work properly and also they bring in bird mites, droppings, and dust that can enter the living area of the home.
TRapper's Wildlife Control can clean out the vent up to 30 feet long which removes the nest, any eggs or young, the adult bird, and then seals the vent on the outside with a plastic bird guard. The price for this is $225.00. Each additional vent that needs protected is $40 per vent. An inspection will determine if any nests in others before installing guard.
This cost does not include the cost of a lift rental should one be needed to safely access the vent to do the work.
No, this is not a trick. You really are seeing this. This is a 4 Foot Tall Starling Nest that was built inside an attic to the top of a Louvered Vent where the starlings were gaining access into the attic
Starling (black bird) Removal