We know that you're looking for a quick-fix when it comes to getting bats away from your home or building, but a quick fix is, sadly, not going to get the job done here. Take the whole bright lights and loud noises theory as an example; it's a really great idea in theory. Bats are nocturnal animals, therefore, not liking the disruption of light or sound. If you were to go into a dark room where bats were roosting, such as in the attic, and then turn the lights on, there's a good chance that all the bats in there would fly off into the sunset, never to be seen again …
… except, they are going to be seen again, in a couple of hours probably.
Bats will always come back to roosting spots they know. Mothers will come back to the same maternity roosts if they are still available, and they will pass the information down to their youngsters too. If your attic has a hole in it all the time, bats always have a way of getting in and out. Yes, you can turn the lights on and turn the radio up all the time, but that will get boring and expensive. Think of the additional electricity costs. Don't you already shout at the kids enough for leaving the lights on when they're not in a room? Using electronic devices to get rid of bats really isn't an eco-friendly or economical way of dealing with things.
It just doesn't make sense to leave the lights on in the attic with the hope that all bats will leave, when exclusion devices and sealing methods would work so much better. In fact, you can even use lights and sounds to hurry the process along if you liked. But using them alone won't work. The holes are still there. The guano is still there, attracting other bats and potentially rodents and scavengers too. The roost is still there, and it's still accessible too. The bats don't really have a reason to leave.
Go back to the Bat Removal
page, or learn about bats in the attic with my Bats in the Attic