Statistically, it’s safer than owning a dog or planting flowers. Flowers attract bees whose stings account for far more human fatality than bats. Just banning bicycles or swimming pools would be hundreds of times more effective in saving lives, but how safe do we really want to be?
Quote from here an excellent website about bats which are messy if they roost in your house and your ceiling isn’t properly sealed, but beautiful especially if you see them in the morning when you are not trying to sleep. And things are never quite as spooky when the sun is out.