If you had bats in your home over the summer, September and October are the best months for conducting a bat exclusion. Bats generally use the same roosts year after year, so they are likely to return to your home in the spring unless you take preventative measures.
Since many populations of bats are in trouble and it is illegal to kill bats, the recommended form of exclusion is some type of one-way door. When attached to their entry points, this allows the bats to leave on their own at night to forage, but does not allow them to get back inside the house.
Because bats can fit into spaces as small as 3/8”, it is recommended you hire a professional to perform a bat exclusion and bat-proof your home. You can find a list of licensed nuisance control operators here: http://wildlife.ohiodnr.gov/species-and-h…/nuisance-wildlife