Bats can look like little angels sometimes
If we set aside the fact that the poor bats are hardly known for their aesthetics, we would still have reasons to jump scared if one of these flew through our window: like mice, bats can carry diseases.
Nevertheless, they are also beneficial for humans. Like squirrels and birds, bats help woods grow by spreading seeds and feeding on plague, preventing other diseases from spreading. Yet, it is hard to think of that while looking at a big bat.