We had the exact same issue about 10years ago. We didn't catch it on time and we had a whole family up there chirping constantly and making an absolute mess of the deck that extended from our master bedroom. As soon as the summer was over and we could make sure they were all gone I sealed up all the possible points of entry with chicken wire. Even worse, three years ago we had a raccoon break off the Whirly Bird on our roof (Vent) and make a nest in our attic. The total devastation of the attic was so sad. They used the bathroom all over the place and destroyed a lot of the insulation. Ended up costing $400 to have them humanely removed. Then we had to replace the insulation and clean. What a disaster. I don't blame you one bit. It's not worth it.