Honeypot ants turn some of their workers into living food jars
In honeypot ant colonies, certain workers are fed until their abdomens balloon to the size of grapes. Too swollen to move, they hang from the ceilings of underground chambers as a living pantry. When food runs short, nestmates stroke their antennae and the stored liquid is brought back up.
These specialised workers are called repletes, plerergates or rotunds, and their dramatic swelling is known as physogastry. Other ants draw food from them by mouth-to-mouth transfer, called trophallaxis. Honeypot ants come from several genera, including Myrmecocystus and Camponotus. Henry C. McCook first documented them in 1881, and William Morton Wheeler described them further in 1908. Bees and some wasps store liquid food in combs or nests, but honeypot ants are unique in using their own bodies as the storage vessel.
The trick lies in the abdomen. In Camponotus inflatus it is made of stiff plates joined by a soft, folding membrane. When empty, the plates overlap and the membrane is pleated; when full, the membrane stretches completely and the plates sit far apart. Ordinary workers rarely stretch that far, but repletes cycle again and again between fully folded and fully extended as they are filled and emptied.
Their honey differs from the bee kind. It is also antimicrobial, but wetter and much lower in sugar than manuka or jarrah honey, because it comes not only from nectar but from metabolites of both plant and animal food. It is slightly acidic, contains phenolic compounds, and holds a sugar of unknown function that remained unidentified in 2023.
The ants live in dry places, from scorching deserts to cool but arid woodland, in the southwestern United States, Mexico, Africa and Australia. One Australian study of Camponotus inflatus found repletes made up 49 percent of a colony of 1063 ants and 46 percent of one with 4019. The larger nest had 66 replete chambers, up to 191 repletes in one, reached 1.7 metres deep, and its biggest replete measured 15 millimetres and weighed 1.4 grams. Workers foraged by day for nectar from mulga trees, and for meat from a dead blue-tongued lizard.
Source: Honeypot ant
