The Ant-Decapitating Fly is a group of parasitic phorid flies that specialize in laying their eggs inside living ants. These tiny flies (genus Pseudacteon) are barely the size of a pinhead, but they’ve mastered a brutal life strategy that earns them the title as the necrotic ninjas of the insect world.
Their Bone-Chilling Life Cycle
- The female fly hovers above a foraging ant, then darts in like a dive bomber to inject a single egg into the ant’s thorax.
- The larva hatches inside and migrates to the ant’s head, where it feeds on the tissue… slowly.
- After about two weeks, the larva releases enzymes that cause the ant’s head to detach from its body.
- The larva uses the now-empty ant head as a cozy pupal chamber, emerging days later as a fully formed fly.
Nature’s most metal Airbnb 😳
Where to Spot Them
Most commonly found in South and North America, especially where fire ants (Solenopsis invicta) live, because they’re the primary victims. These flies have even been intentionally released in some U.S. states to help control invasive fire ant populations!
Look for them in sunny, open areas where fire ants forage: grasslands, disturbed soil, or along sidewalks.
Why They’re Cool
- They’re a biological control dream, helping slow invasive ant populations naturally.
- They’ve evolved incredible precision: some can tell if an ant is already parasitized before injecting.
- They literally cause behavioral changes in the ant before decapitation. The ant often wanders away from the colony to die alone.
- Oh yeah…they decapitate ants and turn their heads into bug cocoons.