So I guess it's a way to keep us from settling in caves...
But I've never heard of bats being so aggressive.
It'd be okay if bats acted defensively if provoked (their current attack system), but it would make a lot more sense for them to be skittish when approached like rabbits, flying quickly away -- This would add value to their wing curios.
Now nighttime is a bad time to be out and about, as well as already settled caves being deadly.
This isn't like the odd bear boar or badger in your camp, this is a constant barrage of bats.