Gaps in siding, spaces under warped fascia boards, spaces between house and chimney, and loose flashing and moldings should be sealed to exclude bats and other invading household pests. Figure 3 . Excluding a Bat Colony When bats do become established in a building where they are not wanted, the best and most permanent solution is exclusion. Seal and bat-proof all other openings that bats do not use, but might use in the future. Plan to do the exclusions in the spring or fall.
Bats give birth in the summer.
Exclusions must not be attempted when baby bats are present, as they do not fly with their mothers until they are almost full grown. Baby bats trapped in the roost by an exclusion will die of thirst or starvation and create a serious odor and fly problem. In Florida, exclusions should not be attempted from May through August. Wait until the young are flying to exclude the colony. 45F. Exclude the unwanted bats by placing one-way devices on the colony's exit points.