seal off from enemy invaders.
Honey ants are generalized scavengers and predators. Sugary carbohydrates are needed for energy. The ants visit flowers and extrafloral nectaries for the sweet rewards, and "milk" homopterans like aphids and scale insects for their sugary exudations called honeydew. Once engorged with liquid sugar, workers return to their nest to share with other colony members.
Protein sources also are necessary, particularly for the growing larvae. Foraging honey ants search for live or recently dead invertebrates, predominantly arthropods; small soft-bodied insects like termites and caterpillars are especially fair game. Individual workers head homeward with pieces of food clasped within their mandibles, while groups of workers may cooperate when retrieving large or struggling prey items.
Like all formicine ants, honey ants lack stingers: rather, they spray fine droplets of formic acid from their abdominal tip. The caustic acid is used, along with pinching mandibles, to help subdue uncooperative prey or to deter colony enemies. Grappling with prey or facing off against their foes, attacking honey ants spread and brace their legs, rapidly curl their abdomens underneath pointing forward, aim and fire. Their chemical weaponry is most effective against small targets; it is useful against mammals or other large animals only if sprayed into highly sensitive tissues like eyes or nostrils.
Given an abundance of sweet repletes, it is not surprising that badgers and other desert creatures sometimes burrow into and plunder honey ant nests. Even some honey ant colonies will raid one another, stealing not only repletes but also brood, that when mature, is "enslaved" as part of the pirating colony's worker force.
As recently as early this century, various Native American tribes and Mexicans regularly excavated honey ant colonies to obtain the savory morsels stockpiled therein. Sweet-toothed human predators typically hold a replete's head and thorax with the fingers, bite off or rupture the fragile abdomen, then suck its contents into the mouth. The so-called "honey" tastes somewhat like molasses, while the ants' bodies, being bitter, are discarded. Perhaps fortunately for honey ants, this practice seems to have fallen by the wayside due to the advent of commercially available candies. These not only taste better but are much less work to procure.
Many social insects, notably honey bees and some wasps, collect and store liquid sweets for later use. However, these insects stow their food within the confines of their nest combs. Honey ants are unique in using their own bodies as living storage vessels.
But why develop repletes? In arid regions, food and water usually are obtainable only for very limited periods. But when available, as during the brief summer rainy or growing season, these resources are present in overwhelming abundance. Under favorable conditions, surplus food gathered by the colony is fed to the repletes for long-term storage. Then, in times of need, the food is regurgitated back to colony members.
While the formation of food-storing repletes seems remarkable, it is merely an exaggerated form of typical ant behavior. Most ants possess expandable abdominal crops (stomachs) for temporarily carrying liquid food back to the nest. When solicited by a hungry nestmate, they regurgitate this liquid and offer a small droplet held between their mandibles. Close observation will reveal that the donor ant's abdomen shrinks as the recipient's abdomen expands. Thus, the crop serves as a "communal stomach" and repletism simply as extreme development of this expandable organ.
In the presence of excess food, repletes can develop from any newly emerged worker, apparently before its exoskeleton and intersegmental membranes harden and become less flexible. In young colonies, it is not uncommon to find small workers serving as somewhat ineffective repletes, with their tiny abdomens distended to the bursting point. However, on an individual basis, major workers make the most efficient honeypots. Hundreds to a thousand or more