Goddamned Bats" and "Bat out of Hell" pages on the Television Tropes & Idioms wiki. I can recall quite a few games I've played in which bats come swarming out of the darkness (usually once you've ventured into a cave or system of tunnels within a cave) and, though easily killed, often attack in such large numbers (and fly in such an unpredictable pattern) that they can become pretty frustrating to deal with.
Even one of my most favorite games of all time, Castlevania: Symphony of the Night, is not without its enemy bats attacking from the shadows without warning. But it's also very bat-friendly, as you will see if you watch the YouTube video below. In this video we see not only how this classic game pairs its hero with a bat as one of many helpful "familiars", but also eventually gives him the power to transform himself into a bat. As such, he can not only fly (and thereby explore previously inaccessible areas) but he can also acquire the "Echo of Bat" ability... in other words, bat sonar or echolocation! Check it out:
In the beginning of this next video, we get to see the bat sonar ability in action. Unfortunately, this is the only part of the game in which that ability is useful. It's a shame they didn't create more areas like this, in which echolocation was necessary in order to navigate safely through complete darkness.
If you'd like to learn more about echolocation in bats, here's a good place to start. Stay batty! ^V^