When it comes to the ruthless headhunters of the insect world, looks can be deceptive.

Take the tiny, seemingly unassuming tropical flies that make their living by slicing the heads off ants, as reported this month in Biodiversity Data Journal.

In the new study, scientists recorded three species of phorid flies, from the poorly known Dohrniphora genus, decapitating trap-jaw ants in the forests of Brazil and Costa Rica. (Related: "There's More Than One Way to Decapitate an Ant.")

The previously unknown behavior was caught on camera by a team led by Brian Brown, curator of entomology at the Natural History Museum of Los Angeles County.

A female fly uses a superlong proboscis tipped with a bladed