Florida’s Formica archboldi ants are not to be messed with. As Newsweek reports, a North Carolina-based researcher recently discovered that the species applies a waxy coat to its body to chemically mimic its intended prey, a kind of trap-jaw ant in the genus Odontomachus. Then, the predator sprays its unsuspecting prey with acid to immobilize it and drags it back to its underground lair, where it dismembers the body and presumably eats everything but the hollowed-out heads.

The Florida ant’s habit of letting the heads pile up in its nest has earned it a pretty grisly nickname: the “skull-collecting ant.” This behavior has been observed since the 1950s. However, scientists have only recently learned how the Florida ant manages to kill trap-jaw ants, which are formidable predators in their own right (they can snap their jaws shut at speeds of over 100 miles an hour).

Researcher Adrian Smith, head of the Evolutionary Biology & Behavior Research Lab at the North Carolina Museum of Natural Sciences, observed the F. archboldi ants mimicking trap-jaw ants at the chemical level by coating their bodies in the same waxy substance that covers their prey. Smith says they’re probably disguising themselves, but the extent to which they do so isn’t yet known.

The ants were also seen shooting formic acid from their abdomens to render the trap-jaw ants motionless. The new findings were published in the journal Insectes Sociaux, and Smith even captured the gruesome action on camera, which you can check out in the video below.

Smith says he’s been fascinated with the ants—which are also found in parts of Alabama and Georgia—since he was an undergrad student at Florida State.

“They’re one of the most badass ants I know of. That’s why I wanted to study them—they decorate their nests with skulls,” Smith told The Verge. “A lot of other ants do cool things, but these are special to me because they’re from Florida, and I’m from Florida."

[h/t Newsweek]