Kill the Mutant Giant Bats

Kill the Mutant Giant Bats was going to be a quest in Van Buren, the canceled Fallout 3 by Black Isle Studios.

Background
Mutant bats live in one of the Blackfoot caves, and are attacking the Blackfoots during the day.

The bats aren't a threat to you unless you're a ghoul (they'd rather eat fruit and bugs), but you can decide to kill them off anyway. If you kill them off, then manti swarms become possible random encounters near the town, and the float text of the Blackfoots in town mention the increased number of mantis from time to time.

Character type completion breakdown

 * 1) CombatBoy - Kills!
 * 2) ScienceBoy - Can poison them!
 * 3) DiploBoy - Can talk some younger tribals to help him kill the relatively harmless giant bats!
 * 4) Stealth Boy - Can sneak about the bat lair during the day and is less likely to wake them all up when murdering sleeping bats!

Source

 * Blackfoot design document