
Bulldog ants are a group of large, aggressive ants belonging to the genus Myrmecia, which is native to Australia. These ants are known for their impressive size, powerful mandibles, and potent stingers. Myrmecia are often called bulldog ants, bull ants, inch ants, sergeant ants, or jumper ants.

Bulldog ants are among the largest ants in the world, with some species reaching up to 1.5 inches in length. The queen ants are even larger, measuring up to 2 inches. They come in various colors, including black, red, brown, and orange, with some species having a combination of colors.

Bulldog ants have strong, powerful mandibles[1] that they use for hunting, cutting food, and defending their nest. These mandibles are well-suited for capturing and immobilizing prey. Like many ants, bulldog ants possess a stinger, which they use to inject venom into their prey or potential threats.

The venom can be painful to humans and may cause allergic reactions in some cases. Bulldog ant venom is among the most toxic venom in the insect world. Unlike in honeybees, the sting lacks barbs, so the stinger is not left in the area the ant has stung.

While attacking an intruder, they grip them and curl their abdomen to inject the venom into the victim’s body repeatedly. In Australia, it is most common to treat these stings with what is known as bush remedies which are comprised of traditional medicines by Aboriginals and Torres Strait Islanders[2].

The tips of broken ferns are rubbed onto the stung area. Emergency treatment is only necessary if the person is showing signs of anaphylactic shock[3]. Before calling for help, the stung person should lie down and elevate their legs. In the Starr sting pain scale[4], a scale that compares the overall pain of hymenopteran stings[5] on a four-point scale, Myrmecia stings were ranked from 2–3 in pain, described as “painful” or “sharply and seriously painful”.

Bulldog ants have relatively good eyesight compared to other ant species, with large, well-developed compound eyes that help them locate prey and navigate their environment. They are primarily solitary foragers, meaning that they do not form large colonies like other ant species.

Instead, they live in smaller family groups, with a single queen and a few dozen worker ants. These ants are formidable predators, hunting a wide range of prey, including insects, spiders, and even small vertebrates like lizards and frogs.

Their powerful mandibles and venomous stings make them effective hunters. Bulldog ants typically nest underground in soil or decaying wood. Their nests can be quite extensive and can consist of multiple chambers. A bulldog ant colony usually has a single queen responsible for laying eggs.


A queen will mate with one or more males, and during colony foundation, she will hunt for food until the brood has fully developed. The life cycle of the ant from egg to adult takes several months. The queen produces worker ants that help with foraging and caring for the brood. Bulldog ant colonies are relatively small compared to other ant species.

They are most active during the warmer months of the year, and their activity decreases during the colder winter months. These ants are known for their aggressive behavior when defending their nest or foraging territory. They will fiercely defend against any threats and have been known to deliver painful stings to intruders.
Footnotes
- Mandibles, in the context of insects and some other arthropods, are paired, strong, and often toothed appendages located near the mouthparts. They play a critical role in various functions, such as grasping, cutting, chewing, and manipulating food. Mandibles are highly specialized in different arthropod species to suit their specific feeding habits and ecological roles. For example, in bulldog ants, as previously mentioned, the mandibles are powerful tools used for hunting and cutting prey. In social insects like ants, mandibles also serve various tasks within the colony, such as nest construction, brood care, and defense. [Back]
- Aboriginals and Torres Strait Islanders are the Indigenous peoples of Australia, each with distinct cultural identities, languages, and traditions. Aboriginals are the Indigenous peoples of mainland Australia, while Torres Strait Islanders are Indigenous peoples from the Torres Strait Islands, which are located between the northern tip of Queensland and Papua New Guinea. They have inhabited these regions for tens of thousands of years, possessing rich oral histories and deep connections to the land. Despite the diversity among Aboriginal and Torres Strait Islander communities, they share a history of colonization, dispossession, and ongoing struggles for self-determination, land rights, and cultural preservation. [Back]
- Anaphylactic shock is a severe, life-threatening allergic reaction that occurs rapidly after exposure to an allergen, such as certain foods, insect stings, medications, or latex. It involves a systemic release of large amounts of histamine and other chemicals, leading to a widespread and often severe inflammatory response. This reaction can cause a sudden drop in blood pressure, swelling of the airways, difficulty breathing, hives, and gastrointestinal symptoms, among other symptoms. Anaphylactic shock is a medical emergency that requires immediate treatment with epinephrine (adrenaline) and other measures to reverse the allergic response and stabilize the individual. [Back]
- The Starr Sting Pain Scale, also known as the Justin O. Schmidt Sting Pain Index, is a system developed by entomologist Justin O. Schmidt to rank and describe the painfulness of insect stings. It categorizes stings on a scale from 0 to 4, with 0 being completely painless and 4 being excruciatingly painful. Schmidt subjected himself to stings from various insects to create this scale, and it has since become a widely referenced tool for comparing the pain intensity of different insect stings. The scale helps researchers and enthusiasts understand and quantify the pain associated with insect stings and bites, contributing to our knowledge of venomous insects and their effects on humans. [Back]
- Hymenopteran stings are the defensive mechanisms employed by insects belonging to the order Hymenoptera, which includes bees, wasps, ants, and sawflies. These stings are typically used to protect their colonies, nests, or themselves from perceived threats. Hymenopteran stings can vary in their potency and effects, with some species delivering painful stings that may cause localized pain, swelling, and allergic reactions in susceptible individuals. The stinging apparatus of hymenopterans consists of a venomous stinger or ovipositor, which can inject venom into the victim. The composition of hymenopteran venoms is complex and varies among species, containing a mixture of proteins and peptides that can elicit a range of physiological responses in the recipient, from pain and inflammation to potentially severe allergic reactions in some cases. [Back]
Further Reading
Sources
- Myrmecia (ant) https://en.wikipedia.org/wiki/Myrmecia_(ant)
- “Bulldog Ant” https://www.animalspot.net/bulldog-ant.html
- “Australian Bulldog Ant” (Jun 24, 2019) https://uspest.com/blog/australian-bulldog-ant/
- “Bulldog Ant” https://aepma.com.au/PestDetail/3/Bulldog
- “5 Unusual Facts About Bulldog Ants” https://www.thefactsite.com/facts-about-bulldog-ants/
- “Bulldog Ant” https://www.bloopatone.com/projects/bgDKr
- Australian Government, Department of the Prime Minister and Cabinet. (n.d.). Indigenous Affairs. https://www.pmc.gov.au/indigenous-affairs/about-Indigenous-Australians