Bats can be a major problem if they get into your roof. Not only do they carry diseases that your family could be exposed to, but the damage to your roof can require costly repairs. With all of the potential problems that come with bats in your roof, getting rid of them is a priority that cannot be put off for long. Fortunately, getting rid of bats is relatively easy.
Wait until spring. Since bats hibernate in the winter, getting rid of them before spring is difficult and can be an exercise in futility. Unless an expert is removing the bats, it's best to wait until spring.
Allow the bats to leave for the night. Since bats will typically leave once in the night, waiting for them to leave and then taking action to keep them out is the only way to really get rid of them.
Note the location from which the bats leave. After the bats have left, getting rid of them is a matter of making sure they cannot get back into the roof. Close up all of the holes, gaps and even small cracks in the roof that could potentially allow a bat in. Temporary measures can be taken to keep them out until the roof can be fixed permanently.
Put bat-proofing measures in place. This should not be done during the summer months, when young are likely left behind, but during the winter when bats are elsewhere to hibernate. Bat-proofing can take many forms, from sealing all of the potential entrances completely to putting bird netting up.
Thoroughly clean the area where the bats lived. Bat guano can lead to infections and diseases in humans.
This article applies to the US only. Please check the legal position on disturbing bats in the UK. See link to Bats and the Law - UK below.