The only way to permanently keep bats away is with a full exclusion done to the home. This will consist of screening gable end vents, sealing behind fascia board along eaves, sealing construction gaps, sealing dormer corners, sealing ridge caps, and any other areas that will allow a bat to enter into the home. If bats are currently present, a bat valve will be installed which is a one-way door that allows the bats to easily leave the home but does not allow them to get back in. Once all bats have left through the bat valve, it may then be removed and permanently sealed. As for sound machines and repellents, no. Although it may seem that it rustles the bats at first, it is simply the activity of your presence. The bats will soon settle down and continue to roost in that area. If there is a food source present in an area, bats will stay put.