Yeah, that's one of the reasons I don't even consider writing anything except memoirs.

Okay, so if the story is fiction, why can't the bats also be fiction?

Perhaps the bats could be an unknown species, or you can have the bats attracted to the cave because of some geothermal (or other) attraction.

I can understand not wanting to violate the laws of physics. Then again, if it were me, I'd insist on making sure something like the phase of the moon is correct for where & when it appears in the sky and other similar details.

Good luck with the re-write!