"Female phorid flies are attracted to fire ants swarming over a disturbed mound or foraging along a trail to food. They hover over ants looking for a preferred individual. (Each phorid species has a particular size range of fire ant workers which it prefers.) When the hapless victim is chosen, the phorid darts in, injects an egg into the ant's body, and explodes away at warp speed. The attack takes a fraction of a second and leaves the ant partly paralyzed and disoriented for a minute or so before she staggers off to join her sisters!

"The injected egg develops in the ant's thorax until after about ten days the ant dies as the larva moves into the ant's head. The head falls off and the larva eventually pupates in the safety of the hard chitin shell that once housed the ant's jaw muscles and brain. Ant pieces are tossed on ant trash piles or middens and adult flies emerge from pupae about 45 days after the original attack. That's the direct effect of mortality that these decapitating flies impose on ants.