Most of us know that insect eating bats are beneficial but most of us are not crazy about having them in our buildings. There are safe methods for excluding bats but the FWC requires they be in place at least 4 days. They also require that they be completely removed by maternity season (which runs from April 15 to August 15). So now is the time to exclude them from your home if you plan to do so.
Read more on this issue, and methods to solve, at http://nwdistrict.ifas.ufl.edu/nat/2015/04/08/what-can-you-do-about-a-colony-of-bats-in-a-building/