Metapleural gland

They are responsible for the production of an antibiotic fluid that then collects in a reservoir on the posterior of the ant's alitrunk.

[1] As of 2023, research has found a metapleural gland convergently evolved in the wasp species Pelecinus polyturator.

This helps to prevent the growth of bacteria and fungal spores[3] on the ants and inside their nest.

It was originally suggested that because this weaving lifestyle also tended to involve an arboreal lifestyle, the parasite pressure above ground was not as great as for terrestrial ants, resulting in a reduced selective pressure to keep this antibiotic gland.

Recent work suggests instead that these ants may just use other antiparasitic defenses such as increased grooming and venom.