Phragmosis
Guides
Carebara
Marauder Ants, Carebara Thief Ants
Carebara is a large genus of myrmicine ants comprising over 200 species distributed worldwide in tropical and Afrotropical regions. These ants are among the smallest known, with workers often barely visible to the naked eye. The genus exhibits remarkable worker polymorphism, including specialized soldier castes with phragmotic (door-blocking) head shapes in some African species. Queens are notably much larger than workers, creating one of the most extreme size dimorphisms in ants. Many species are cryptic inhabitants of soil and leaf litter, with poorly known biology.
Cephalotes texanus
Texanus-group Turtle Ants
Cephalotes texanus is a species of arboreal ant in the genus Cephalotes, commonly known as turtle ants. The species is characterized by its ability to glide through the air when falling from trees, a behavior facilitated by enlarged, flattened legs. It exhibits phragmosis, a defensive adaptation where soldiers use their uniquely shaped heads to block nest entrances. The species inhabits pre-existing cavities in wood, particularly those created by longhorn beetle larvae, rather than constructing its own nests. Native to Texas and northeastern Mexico, it was first described by Felix Santschi in 1915.
Colobopsis
Gate-keeper Ants
Colobopsis is a genus of ants in the subfamily Formicinae, first described by Mayr in 1861 and containing approximately 95 species. The genus is distinguished by pronounced worker caste dimorphism, with major workers possessing phragmotic (truncate, plug-shaped) heads used to block nest entrances. Members of the Colobopsis cylindrica group exhibit autothysis, a defensive behavior where minor workers rupture their gaster to release sticky, irritant mandibular gland secretions. The genus nests primarily in plant material including wood, galls, and dead branches. Colobopsis was historically treated as a subgenus of Camponotus but was restored to full generic status following a 2015 phylogenomic study that identified it as sister to all remaining Camponotini.
Colobopsis impressa
Common Gate-keeper Ant
Colobopsis impressa is a species of arboreal ant in the subfamily Formicinae, commonly known as the Common Gate-keeper Ant. The species belongs to a genus noted for specialized defensive morphologies, including major workers with plug-shaped heads used to block nest entrances. While detailed species-level studies are limited, the species has been documented across Southeast Asian forests. Its biology appears consistent with the broader Colobopsis cylindrica species group, though specific behavioral observations for C. impressa remain sparse.
Cyclocosmia
cork-lid trapdoor spider, Oreo spider (misnomer)
Cyclocosmia is a genus of mygalomorph trapdoor spiders in the family Halonoproctidae, comprising thirteen species distributed across North America (USA, Mexico) and Southeast Asia (China, Thailand, Vietnam, Laos). These spiders are distinguished by their unique abdominal morphology: an abruptly truncated, hardened posterior disc strengthened by ribs and grooves, used to seal burrow entrances when threatened. The genus was first described by Anton Ausserer in 1871 and serves as the type genus for Halonoproctidae. Species are long-lived, slow-maturing, and have demanding habitat requirements that make them rare in collections despite local abundance.
Cyclocosmia truncata
Ravine Trapdoor Spider
Cyclocosmia truncata is a cork-lid trapdoor spider native to the United States. It constructs burrows in soil and employs a distinctive defensive behavior called phragmosis, using its rigid, disc-shaped abdomen to plug the burrow entrance when threatened. The species belongs to the mygalomorph spider group, which includes tarantulas and other trapdoor spiders. It is not considered dangerous to humans despite possessing venom typical of spiders.
Elipsocidae
Damp Barklice
Elipsocidae is a family of barklice in the order Psocodea, containing approximately 130 species across more than 30 genera. Members are characterized by a free areola postica in the wing venation, and many species are apterous (wingless). The family exhibits diverse ecological adaptations, including crypsis and substrate-specific habitat selection in some species, and potentially phragmotic behavior in others.
Kalotermitidae
Drywood Termites
Kalotermitidae, commonly known as drywood termites, is a basal family of termites with 21 genera and 419 species, making it the second most diverse termite family after Termitidae. The family exhibits a cosmopolitan circumtropical distribution and is characterized by colonies that inhabit sound wood without soil contact. Unlike many termites, Kalotermitidae lack a true worker caste; instead, immature individuals called pseudergates perform worker functions before developing into soldiers or reproductives. The family includes significant pest species such as Cryptotermes brevis and Incisitermes minor, which cause economic damage to wooden structures, furniture, and utility towers worldwide.
Pheidole obtusospinosa
Blunt-spined Big-headed Ant
Pheidole obtusospinosa is a species of big-headed ant in the genus Pheidole, characterized by soldier ants with enlarged, squared heads used for nest defense. The species belongs to the hyperdiverse ant genus Pheidole, which contains over 1,000 species globally. Soldiers of this species have been observed using their modified heads to block nest entrances against intruders, particularly army ants such as Eciton burchelli. The species was described by Pergande in 1896.