Scientists have recorded the first video footage of a tiny killer fly catching its prey in mid-air.
Using a species called Coenosia attenuata, they investigated how the 4mm-long insect decides when to pounce.
The C. attenuata is great at killing other airborne critters - including fruit flies.
Scientists discovered that the little predators are not very good at judging the size of their target.
Instead they decide whether to strike, sometimes based on how fast a potential meal is buzzing past.
C. attenuata is an unfussy eating machine, explained Dr Paloma Gonzalez-Bellido.
"It didn't look like they have a template for what they're looking for," she told the BBC.
"They go after things that are very slow, after things that are fast, after things that are white, things that are black..."
The experiments appear in the journal Brain, Behaviour and Evolution.
Footage courtesy of Trevor Wardill and Paloma Gonzalez-Bellido, University of Cambridge