[3] The process, leading up to mortality, takes 4–10 days, and includes a reproductive stage where fruiting bodies grow from the ant's head, rupturing to release the fungus's spores.

[4] The new molecular phylogenetics studies contradicted the older classification and moved all Cordyceps species forming a sister group with Tolypocladium, into Ophiocordycipitaceae.

[5] Following this study, multiple traits such as the production of darkly pigmented, hard to flexible stromata were defined as characteristics of the family Ophiocordycipitaceae.

Following this, a study conducted in Brazil delimited, using morphological comparisons of the ascospores, germination processes, and asexual morphs, four different Ophiocordyceps species.

[7] More recently in 2018, 15 new O. unilateralis species were described based on classic taxonomic criteria, and macro-morphological data with a deeper focus on ascospore and asexual morphology.

At the end of its life cycle, O. unilateralis typically generates a single, wiry yet pliant, darkly pigmented stroma which arises from the dorsal pronotum region of the ant once it is dead.

It exhibits a single stroma with a Hirsutella asexual morph, which arises from the dorsal neck region of the dead ant and produces a dark brown perithecia attached to its stalk.

[5] In tropical forests, the ant species Camponotus leonardi lives in the high canopy and has an extensive network of aerial trails.

The ant climbs up the stem of a plant and uses its mandibles with abnormal force to secure itself to a leaf vein, leaving dumbbell-shaped marks on it.

The ants generally clamp to a leaf's vein at a height of 26 cm above the forest floor,[10] on the northern side of the plant, in an environment with 94–95% humidity and temperatures between 20 and 30 °C (68 and 86 °F).

[12] When the dead ants are moved to other places and positions, further vegetative growth and sporulation either fails to occur or results in undersized and abnormal reproductive structures.

[14][15] Once the mandibles of the ant are secured to the leaf vein, atrophy quickly sets in, destroying the sarcomere connections in the muscle fibers and reducing the mitochondria and sarcoplasmic reticular.

[11] This is followed by the fungus controlling the climbing of the ant and the locking of its jaw (and subsequent death) onto a leaf around 25 centimetres above the ground, which is thought to be the optimal height for fungal spore growth and dispersion.

[20] Studies have shown that O. unilateralis reacts heterogeneously by secreting different metabolites according to the host tissue it encounters and whether they are live or dead.

However, more research is needed to determine whether other fungal metabolites interact with the host brain to cause higher levels of sphingosine and GBA.

[13] More in-depth research is needed for the identification of other fungal compounds which act to atrophy the mandibular muscles, and for the understanding of their exact effects on the ant.

[13] Its distribution includes tropical rainforests located in Brazil, Australia and Thailand, and temperate forests found in South Carolina, Florida and Japan.

[5] A 48-million-year-old fossil of a leaf stem exhibiting dumbbell-shaped marks characteristic of those made by an ant in the death-grip of Ophiocordyceps unilateralis was discovered in the Messel pit (Germany).

[3] It is thought that large precipitation events at the beginning and the end of the rainy season stimulates fungal development,[3] which leads to more spores being released and ultimately more individuals being infected and killed.

These natural products are reportedly being investigated as potential leads in discovery efforts toward immunomodulatory, antitumor, hypoglycemic, and hypocholesterolemic targets.

These attributes also make it a prime candidate for antituberculosis testing in secondary TB patients, by improving symptoms and enhancing immunity when combined with chemotherapeutic drugs.

species as they can produce and release within the air, clear and thin-walled spores which are susceptible to environmental conditions such as UV radiation and dryness.

[34] In fact, studies suggest that the short viability of the fungal spores lead to the need of somatic investment (growth/survival) by the parasite in order to sustain the growth of the fungus' fruiting body on its host, thereby enabling successive reproduction.

[23] In areas where O. unilateralis is present, C. leonardi builds its nests high in the canopy, and has a broad network of aerial trails.

These trails occasionally move down to the ground level, where infection and graveyards occur, due to canopy gaps too difficult for the ants to cross.

Additionally, more evidence participates in the favour of this defence method being adaptive as it is not observed in undisturbed forests where the zombie-ant fungus is not present.

Also, in episode two of the 2023 television series The Last of Us on HBO Max,[35] Ophiocordyceps unilateralis is revealed to be the primary cause of the infected outbreak and subsequent collapse of human civilization.

[36] In the 2014 novel The Girl With All The Gifts, its 2016 film adaptation and its prequel novel entitled The Boy on the Bridge, all written by M. R. Carey, a strain of Ophiocordyceps unilateralis is similarly able to infect the human population through exchange of bodily fluids, leading to an apocalyptic world inhabited by zombie-like "hungries" who attack non-infected.

The video game Cult of the Lamb features an ant character named Sozo who is implied to be under the influence of a parasitic fungus similar in nature to Ophiocordyceps unilateralis.

Upon returning to his lair after completing his quest line, the player finds him dead on the ground, with the fungus on his head split in two to spread its spores.