Invertebrates
Honeypot Ant
Myrmecocystus mexicanus · also called honeypot ant, honey ant
In a honeypot ant nest, some of the workers stop being ants in any ordinary sense and become furniture. Fed sugary liquid by their nestmates until the abdomen swells to the size of a grape, they climb to the roof of an underground chamber, grip on, and hang there for the rest of their lives — living jars that the colony taps for food when the desert dries out.
Overview
Honeypot ants live in deserts and dry grasslands on several continents; this species is from the south-western United States and northern Mexico. Ordinary workers are a few millimetres long, but a loaded replete has an abdomen ballooned to the size of a small grape, amber and translucent, and can barely move. The ants gather nectar, sap, honeydew, and insect fluids.
Living storage jars
Selected young workers are fed by other ants until their crop is packed with liquid. They then hang from a chamber ceiling as the colony’s food reserve: in lean times, a hungry ant strokes a replete’s mouthparts and it regurgitates a droplet. A nest may hold hundreds. The strategy has evolved independently in several unrelated ant groups.
A traditional sweet
Aboriginal Australians dig honeypot ants — yarumpa or tjala — and eat the repletes live for their honey-like contents, as do Indigenous peoples of Mexico.
Ant wars
Rival colonies compete through ritualised stilt-walking displays, and a colony judged weaker may be raided and have its repletes carried off.
Status
Honeypot ants are not assessed and widespread in arid regions, though local nests can be depleted by heavy digging.
Honeypot Ant: common questions
How does an ant turn into a honeypot?
It is not born that way. In a young colony, certain newly emerged workers are selected, usually the larger ones, and are fed continuously by their nestmates through mouth-to-mouth transfer. Ants have a crop, sometimes called the social stomach, that stores liquid food for sharing rather than digesting it, and in a replete this crop is filled far beyond normal, stretching the soft membrane between the hard plates of the abdomen until the whole rear of the ant is a taut, shiny sphere many times its original size. Once a worker is that swollen it can no longer forage or do much of anything, so it climbs to the roof of a storage chamber, grips on, and hangs there for the rest of its life as part of the colony's larder.
What do the repletes store, and how is it used?
They store a sugary liquid, mostly nectar and the honeydew that aphids and scale insects excrete, along with water and some of the fluids from insect prey. During good times, foragers bring in more than the colony needs, and the surplus is pumped into repletes. During bad times, when little or nothing can be found outside, a hungry ant approaches a replete and taps its head and jaws in a specific way, prompting the replete to bring up a drop of the stored liquid, which the forager then shares around. In this way the colony can ride out weeks or months of drought.
Can you really eat honeypot ants?
Yes, and people have for a very long time. In central Australia, honeypot ants are a valued traditional food, and family groups dig down along the ant galleries, sometimes more than a metre, to reach the chambers of repletes, which are eaten straight away by biting off the swollen abdomen and sucking out the sweet contents. The taste is often compared to a light, slightly tart honey or nectar. The same practice occurs in parts of Mexico and the American Southwest. The rest of the ant is usually discarded, and careful diggers leave enough of the nest to recover.
Why do honeypot colonies fight each other?
The repletes make a colony worth robbing. A nest full of stored liquid represents months of foraging effort concentrated in one place, so a rival colony that can seize it gains an enormous head start. Honeypot ants of some species settle disputes over territory and dominance with elaborate tournaments, in which large numbers of workers from neighbouring nests meet at the boundary and perform stiff-legged, stilt-walking displays without actually fighting. If these displays reveal that one colony is much weaker, the stronger one launches a raid, kills or drives off the defenders, and carries the captured repletes back to its own nest.