This area gives you an oversight on the genus Myrmecia.


Commonly known as Bull ants, Inch ants or Jack Jumpers, are these ants the largest ants in Australia. Large eyed, brightly coloured and armed with powerful mandibles and a painful sting, these ants are also some of the easiest to recognise.

Myrmecia nigriscapa

From the 89 known species of Myrmecia, 88 occur only in Australia. The remaining species is found in New Caledonia where it is rare.

Bull ants can be found in a wide range of habitats throughout Australia, but are most abundant in southern regions.

Myrmecia are considered phylogenetically primitive ants, which is shown in their primitive anatomy and social habits.

The queens are similar in appearance to the workers.

The workers forage in a solitary manner, and when they discover food outside the nest they bring it home alone, without trying to recruit their nestmates.

Like wasps, the workers gather two kinds of food: nectar to feed themselves and insect prey mainly to give the larvae.

They use only a limited from of chemical communication (Robertson, 1971, Markel in Frehland et al., 1985).

Bull ants are aggressive, have excellent vision and can run very quickly across the ground. The smaller jack jumpers can cover ground rapidly by using a series of short jumps.

If disturbed, they will head straight for the intruder to chase him away from the nest.

The sting of these ants can be very painful and can cause dead as a result of allergic reactions (Clark, 1986). The venom delivered by the sting is similar to that of bees or wasps.


Open bushlands, heath, woodland and forests, as shown on the pictures, are typically habitats for several species of Myrmecia.

These habitats are mostly half shaded areas with more or less open plant cover. They occur seldom in thick forest, more likely in clearings or at the forest border.


Known as solitary predators, the workers hunt singly on the ground or in low vegetation. They hunt small insects and spiders as food for their larvae.(Gray, 1971, 1974) They also collect nectar and plant juices for themselves. Many plants attracting ants with sugar-producing organs, called extrafloral nectaries.(Beattie, 1985)

Most species forage during the day but a few will also forage at night.

A worker of Myrmecia pilosula ( known as Jack Jumpers ) foraging on a tree:

It is common for Myrmecia to forage on vegetation. Even the large species are skilled climber and can often be observed climbing up small shrubs and trees.

They drop down to the ground of disturbed, than it can happen that they land inadvertently on a person.


Workers of most Myrmecia species lay trophic eggs to feed larvae or nestmates with.(Freeland, 1958) These ants have only an primitive form of what is commonly known as communal stomach.(Eisner, 1957) Instead they share food by laying trophic eggs.


Nest are mostly located in soil, often with a mound and are small with only a few hundred workers. But some species have large nests with a few thousand workers. Others species nest in rotten logs and one species in the northern rainforest nests in epiphytic ferns.

Here a nest of Myrmecia (Kangaroo Island):

Myrmecia pilosula (Kangaroo Island) worker guarding the nest entrance:

The nests of some species have very hidden entrances just wide enough to let only one or two workers pass through. Myrmecia pilosula, Blue Mountains:


Here a small nest of a young colony of Myrmecia nigrocincta...

... and a large nest with a small mound:

Myrmecia nigrocincta workers returning to their nest:


No mound but a large entrance hole marks this nests of Myrmecia nigriscapa on Kangaroo Island:

Other nests are large with huge mounds, the entrance a few centimeters in diameter.

In shaded areas a large mound raising high over the surrounding terrain may help to catch more sun and thereby provide better temperatures for the ants and their brood inside the nest. Other ants achieve the same effect by decorating their nests with small stones and pebbles.

Here a large Myrmecia desertorum mound covered with plant material:


A worker of Myrmecia nigrocincta has captured a golden coloured ant of the genus Polyrhachis:

Myrmecia nigrocincta is also a jumping species. Not all species are abel to jump,

that´s something more widespread amongst the smaller species.


This worker of Myrmecia nigriscapa has captured a small grasshopper:

The workers of Myrmecia hunt singly and they only capture prey which they can carry back to the nest by themselves. They don´t work together like other ants do.

The prey is often smaller then the worker or of the same size.

They search actively for prey. They walk around peering in every gap or searching under leafs or fallen bark. They also climb on plants and flowers, investigating every twig and leaf.

If a worker discovers an insect it grabs it with its mandibles, instantly stinging it. The venom kills invertebrates very fast which enables the ants to capture even spiders, wasps and bees.


Brood care

The queen of many species are cyclic egg laying, starting around the time the larvae turn to pupae, the queen will lay new eggs. That takes only a few days in which she will lay quite a large batch of eggs.

After hatching the larvae are separated in differed piles depending on their size.

After around three weeks the larvae are ready to pupate. Then they need adult ants to cover them with sand. That is to support the larva during cocoon spinning.

The pupae are kept in the driest chambers of the nest. They are very sensitive about moisture:

Four to five weeks later the adult ants are hatching. They´re sallow at first and it takes them a few days for hardening their exoskeleton and getting colour.


Most Myrmecia species have large, winged queens.

They leave the nest to mate and to establish new colonies in suitable locations.

The newly mated queens of Myrmecia are known to occasionally leave their nest to hunt insect prey for their larvae. Known as partially claustral colony founding.(Clark 1925; Wheeler, 1933; Haskins und Haskins, 1950, 1951) After the first workers have emerged the queen will remain in the nest for the rest of her life.

Here a young, still sallow queen of Myrmecia pavida:

And here a male of Myrmecia chrysogaster:

Some species lake this type of queens and have worker-like queens instead.

Other species are even temporary social parasites, founding new colonies by invading a established colony of another species and killing its queen, the workers then raising the brood of the invading queen.

Predators and other threats.

Many animals feed on ants, including spiders, predatory invertebrates, birds, lizards and mammals. 

Assassin Bugs (Gminatus australis) are skilled hunters and can capture prey their own size. They often cover themselves with soil or sand for camouflage:

Redbacks (Latrodectus hasselti) are very successful in hunting ants. Vertical trip-lines of the web run to the ground and snare any ant that bums into them.

Here a web containing the remains of at least three different ant genera, Camponotus, Leptomyrmex and also Myrmecia:

Echidnas (Tachyglossus) feed on ants and termites and break open their nests to reach the occupants:

But also are humans a threat to these ants.

Nest are often destroyed in residential areas and the altering and demolishing of ecosystems could be devastating for populations of some species.

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