Block the entrance
It is really difficult to find out the entrance where these bats come in from into the attic. Once you have found that, you will have to look for some DIY techniques to create a one-way net or maybe some other ways out there to block their entrance and still give them a way to fly out. You need to make sure whatever it that you build is or set up is efficient enough not to let them enter once they are out.
You also need to make sure there are no young ones or female bats inside before you block the entrance. However, it may not work if you do not do it properly, so for Bat removal from house you must rely on experts. Calling wildlife removal services near your area will make things easy.
Why call professionals quickly?
The best way is to always rely on professionals and there are a lot of entities out there to help you with this. Their approach is completely different and is based on facts and figures and their experience in the field. The professionals will not only consider the attic and the bats but will also go to the extent of identifying the species of the bats that have inhabited your attic and the acoustics of the house as well as the surroundings before they even take any action. Once they drive them away there are hardly any chances of them returning to your home.