The bloatfly larva is a type of ammunition in Fallout 4.


The bloatfly larva (syringe) is a small syringe similar in appearance to a tranquilizer dart. It is not actually considered ammunition, instead located under Aid. Accordingly, it is not weightless, though it does weigh very little.


Glass (1)
Psycho (1)
Icon range
Icon level
Bloatfly larva (1)


By itself, the bloatfly larva syringe does little damage. However, when injected into an enemy, there is a 10% chance that a bloatfly will spawn from their corpse if they die within 30 seconds of the hit. This can be used to create a distraction, as the spawned bloatfly will be hostile towards everyone around them (the player included). Spawned bloatflies can be any variant of Bloatfly: Black, Festering, Glowing, and even Legendary versions of each. Thus, the bloatfly larva syringe can be a useful way to "farm" Legendary enemies for valuable loot without reloading saves.

Weapons using this ammunitionEdit



  • A spawned bloatfly will also be hostile to any other nearby NPCs.
  • It is one of the crafting materials required to build the bloatfly mounted head.
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