There are three things you can do to discourage further bat activity. One, screen the area off to eliminate access. If you do this, you cannot close the area off completely. The screen will need to be constructed so there is a “one way” passage out, so the bats can get out but not back in. When they are gone, screen off the roost to prevent recolonization. Third, place a spotlight or other bright light to continuously illuminate the dark area currently being occupied. The continuous light will cause the bats to leave. Again screen off the area after the bats have vacated. Remember, lights can be hot, so hang the light or shield it, so you do not start a fire.