Ant nest beetles (subfamily Paussinae) or paussines, some members of which are known also as flanged bombardier beetles, are a large subfamily within the ground beetles (Carabidae).The tribes Metriini, Ozaenini, Paussini and Protopaussini are included in the subfamily.
Rarely seen in the open, except at lights, most Paussinae are obligate or facultative myrmecophiles, living within the nests of ants, predatory on ant larvae and workers. Many have elaborate antennal structures and body parts flattened. Paussines are moderate sized (6–20 mm), characterised by glandular hairs that produce secretions attractive to ants and by the odd antennal structures of many species. Their pygidial glands can produce explosive secretions, with a spray of quinones that are directed forward by flanges at the posterior end of the elytra, giving them the other name of flanged bombardier beetles although they are not particularly close relatives of the typical bombardier beetles (Brachininae).