broke my screen on the outside and inside, then proceeded to move in, and bring all their friends.
We sat outside at dusk and counted them as they left, then moved in and put a wire screen on the outside, and eliminated a couple of stragglers. After much clean up and re-insulating, thought I was done. Then came home and as entering my door at the other end of the house, noticed multiple guano droppings. They had come back, and were in the louvers of the other vent, but not inside... After a spray with the hose which resembled the beginning of the bats on Scooby Doo, they also exited and another screen put on that end. So far, so good....