Although the exact host is unknown, this beetle almost certainly lives in an ant nest. This lifestyle is known as , and you wouldn't believe all the crazy species that make a living this way. Paussinae may be using those antenna to communicate with their ant hosts, but beetles in this group are generally collected only at light traps; so most of their natural history remains a mystery. Some researchers have reported ants using the antenna as handles to relocate the beetles. The plate below shows the astounding diversity of antenal morphology in the subfamily. It's a great example of 19th century naturalist drawing, by
Primitive Paussinae generally have standard mouthparts and thick exoskeletons, while more derived species are lighter and have spoon shaped mouthparts specially adapted to receive regurgitated food directly from ants. All members of the group can mix quinones and gases to produce an explosive self defense, evolutionarily independent of but extremely similar to the famous Bombardier beetles, a different lineage of the Carabidae.