thumb|[[Myrmecocystus honeypot ants, showing the repletes or plerergates, their abdomens swollen to store honey, above ordinary workers]]
Honeypot ants, also called honey ants, are ants which have specialized workers—repletes, plerergates or rotunds—that consume large amounts of food to the point that their abdomens swell enormously. This phenomenon of extreme inflation of the trunk is called physogastry. Other ants then extract nourishment from them, through the process of trophallaxis. They function as living larders. Honeypot ants belong to any of several genera, including Myrmecocystus and Camponotus. They were first documented in 1881 by Henry C. McCook, and described further in 1908 by William Morton Wheeler.
Behaviour
Many insects, notably honey bees and some wasps, collect and store liquid for use at a later date. However, these insects store their food within their nest or in combs. Honey ants are unique in using their own bodies as living storage, used later by their fellow ants when food is otherwise scarce. Designated worker ants, called "repletes," are the main group that store food for the colony. Repletes are fed by other worker ants until their abdomens become swollen with honey. This extreme growth causes the repletes to become mostly immobile as they act as the "living pantry" for the colony. When the liquid stored inside a honeypot ant is needed, the worker ants stroke the antennae of the honeypot ant, causing the honeypot ant to regurgitate the stored liquid from its crop.
Anatomy
thumb|Honeypot ants compared to a human hand. The dark dorsal [[sclerites are widely separated by the stretched arthrodial membrane of the inflated abdomen of each replete.]]
The abdomen of species like Camponotus inflatus consists of hard dorsal sclerites (stiff plates) connected by a softer, more flexible arthrodial membrane. When the abdomen is empty, the arthrodial membrane is folded and the sclerites overlap, but when the abdomen fills the arthrodial membrane becomes fully stretched, leaving the sclerites widely separated. Unlike ordinary workers, in which the arthrodial membrane is rarely stretched to its limit, repletes repeatedly cycle between a tightly folded, overlapping configuration and an extreme, fully extended state as they are filled and drained.
Honey
The honey from honeypot ants is unique. Like bee honey, it has antimicrobial effects against pathogens and decay organisms, but it differs from bee honey, for example in having a higher moisture content. Honeypot honey has a significantly lower concentration of sugar than bee honey from manuka and jarrah for example. The ant honey is not concentrated only from nectar and other sweet components of the diet, but also from metabolites of plant and animal food sources in general. The honey has a slightly acidic pH, and contains phenolic compounds. It also contains a disaccharide of unknown function, that still was unidentified in 2023.
Ecology
Myrmecocystus nests are found in a variety of arid or semiarid environments. Some species live in extremely hot deserts, others reside in transitional habitats, and still other species can be found in woodlands which are somewhat cool but still very dry for a large part of the year. Honey pot ants have been reported to be in the USA (specifically Colorado and New Mexico), Mexico, the African continent, and Australia.
Recent findings
Bee honey is an effective natural remedy for a wide range of ailments. But very little research has been done on other types of honey, produced by different insects, up until recently. The antimicrobial activity of honey from honey pot ants was tested and compared to the antimicrobial activity of bee honey. It was found that honeypot ant honey has activity against bacteria, yeast, and mold. When honey pot ant honey was compared against jarrah or manuka bee honeys, a distinctly different activity profile was found. Honey pot ant honey outperformed the other two honeys against some pathogens, but exhibited low/no activity against other ones.
- Camponotus of Australia
- Anoplolepis and Tapinolepis of South Africa
- Prenolepis of North America For these indigenous groups, the honey pot ant represents their Dreaming or Tjukurpa, the philosophy based on the spiritual connection between people and things.