Scientists are taking a closer look at a species of ant in Florida that decorates its nest with the skulls of other ants it has killed. As if that wasn’t macabre enough, they have now discovered it kills its enemies by mimicking them, then spraying them with acid.

The Florida ant Formica archboldi has been the subject of study for more than 60 years. Their habitat is restricted to the Southeastern U.S., mainly found in Florida and parts of Alabama and Georgia.

Upon its discovery, experts soon noticed its nests were full of the decapitated heads of trap-jaw ants. Species from this carnivorous genus (Odontomachus) are known to be fearsome predators—so at first researchers thought maybe Florida ants moved into former trap-jaw nesting sites.

Alternative theories suggested the Florida ants were some sort of specialized predator that goes around hunting trap-jaw ants.

In a study published in the journal Insectes Sociaux, Adrian Smith, from North Carolina State University, has now analyzed what happens when the Florida ants attack jaw-trap ants. He found Florida ants chemically mimic the trap jaw ant by making a layer of wax that covers the surface of the ant the same as the wax that covers its prey.