Depends on where you are in the US and get the scare of your life.
Up here bats are funny Little fellows, most are incest eaters and no problem, small and can curl up into a quarter size and hide behind a picture frame.
Problem is these are social animals and want to roost among their own. Sleep all day and come out at night, some what like cats.
Depending on the kind of Bat, if a few are in your home you will seldom know it unless something wakes them up.
You may wonder why you are the only family in an apartment building to have no ants, roaches or
bed bugs. Could be the pesky bats are taking care of that.
Bats are hard to catch, but just open a window with a screen the bat will go for it and close the window.