They are usually found around graveyards, buildings, or pools of radiated water in groups of three to five. Weak by nature, their attacks have very little effect. Their main attack consists of spiked larvae launched from a distance. They are relatively easy to kill in close combat, even should the attacker lack any substantial skill in Unarmed or Melee Weapons, as they have very few Hit Points.
Although it can be a bit tricky to hit them with a ranged weapon without the assistance of V.A.T.S. as they tend to flit about in sporadic patterns, ordinary bloatflies won't initiate combat themselves unless the player approaches quite close—so with patience and timing they can be picked off with sneak attacks from range in complete safety, always waiting for hidden status before firing each shot.
The normal variant with all of the attributes noted above.
A legendary variant can be found in Big MT, at the mysterious cave. It is considerably larger than a normal bloatfly, and has a pale green aura, making it easy to spot in the cave. It also flies much higher, making striking it with melee weapons difficult or entirely impossible. Unlike normal bloatflies, it fires a highly damaging (300 damage, equal to that of deathclaw alpha male) plasma-like projectile from its abdomen, the strength of which is such that even the strongest of attackers will be killed after just a few shots. When killed, it explodes in a manner similar to a plasma grenade, leaving a pile of goo instead of a corpse. Its brain can be targeted in V.A.T.S., and if crippled, will cause it to frenzy. It has twice the health of the legendary deathclaw and deals nearly twice the damage.
PCPlaystation 3Xbox 360 After being killed by the legendary bloatfly, and reloading the autosave in the tunnel entrance, the legendary bloatfly may not have the characteristic green glow.[verified]
PCXbox 360 The legendary bloatfly won't spot the Courier hiding in the cave tunnel. Shooting the legendary bloatfly will make it hover in the same place and the Courier will be in a state of [CAUTION] if the player attacks it from the tunnel.[verified]