Bat removal, bat control and bat exclusions during the Fall months is often the best times to complete bat eviction. During the beginning of fall all juvenile pups are in full flight and aren't at risk of being trapped into their dwelling area (attic, eves, walls, vents, etc.). Fall months are often cool, but most times the nights are still warm enough for all the bats to leave their roost for food and water. Once the temperatures drop below 40 degrees at night and frost line hits the food source will die out and the bats can not survive with out relocating or hibernation. Bats will tend to move from the rafters of your attic, the soffits, and outside vents down underneath the insulation to find an area above 40 or 50 degrees where it is most comfortable for them to survive.