Beware the jack jumper ant


Bec Crew


Bec Crew

Bec Crew is a Sydney-based science communicator with a love for weird and wonderful animals. From strange behaviours and special adaptations to newly discovered species and the researchers who find them, her topics celebrate how alien yet relatable so many of the creatures that live amongst us can be.
By Bec Crew 9 August 2021
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Many of us grew up fearing bull ants, but have you ever been stung by a jack jumper ant? If you have, you’ll likely never forget it.

Capable of sending an allergic human into anaphylactic shock, the jack jumper ant is weirdly aggressive, and in very rare circumstances, its venom can be fatal. 

Native to Australia, and found most commonly in the southeast of the mainland, as well as Tasmania, the jack jumper ant (Myrmecia pilosula) is named for the enthusiastic jumping behaviour it displays when agitated. It’s also known to hop from one high place to another, propelling itself with its incredibly strong – and tiny – legs. 

If you happen to make contact with a jack jumper ant, you don’t just have those huge, serrated jaws (mandibles) to contend with. These ants also have a powerful sting that can be inflicted over and over again. 

Fortunately, researchers have come up with an ingenious solution to the jack jumper problem. 

In Tasmania, where it’s estimated that about 3 per cent of the population is at risk of having an allergic reaction to a jack jumper bite or sting, which can range from mild to severe, the government has established the Jack Jumper Allergy Program at the Royal Hobart Hospital. 

By injecting patients with small amounts of the venom over several years, the program helps people – both adults and children – to build up their immunity.

Not that jack jumper ants are all about that sting. They’re a fascinating and complex species, known to live for around a year in the wild, which is impressive for an insect, and speaks to their ability to protect each other from predation and nest destruction.

Related: Australia’s native bull ants are really just wingless wasps

They’re relatively large ants, growing to almost 1.5 cm long, with the queen ant growing to be slightly larger still. They feed on other invertebrates, and can bring down creatures much, much bigger than themselves, such as grasshoppers and huntsman spiders. 

Jack jumpers have the honour of belonging to one of the most fascinating groups of ants on the planet: the Myrmecia genus

Boasting more than 90 different species, most of which are native to Australia, the Myrmecia genus includes the wonderfully named ‘buck-toothed bull ants’ from the Myrmecia tepperi group, found in parts of south-western and south-eastern Australia, and the tiny ‘baby bull ants’ from the M. urens group, found all along the Australian coast. 

What’s incredibly sweet about baby bull ants of the M. urens species is that they can pollinate the Australian fringed hare orchid (Leporella fimbriata) – one of the few cases in nature of ants pollinating plants. 

The orchid, found in southern Australia, is extremely cool. Look how triumphant it is!

(Image credit: James Peake / Alamy Stock Photo)

Parts of the orchid mimic the look of a baby bull ant queen, which entices winged males to try and mate with them. This action, with the males going from orchid to orchid, rubbing their bodies on them, works to pollinate the flowers.

It can also get quite messy, as you can see here: