Decoding the reason why bullet ants have the 'most painful sting in the world'

Researchers have discovered that the ant species has the "world's most painful sting" because its toxins travel directly to human pain nerves .

Unlike the substances found in snake and scorpion venom, the toxins of insects like ants affect the body in a way never seen before.

Researchers from the University of Queensland studied Australian green ants and South American bullet ants , both of which have stings that cause intense and long-lasting pain.

When ants bite humans, their toxins go straight to the human's pain nerves - (Photo: NEW ATLAS).

Green ants are found all over Australia. They like to nest under most grasses and often go unnoticed until someone is stung, resulting in a burning sensation.

Bullet ants live in the humid lowland rainforests of Central and South America. They are named for the pain they cause when stung, which is comparable to the pain of being shot.

A bullet ant can cause severe muscle spasms and burning sensations. The late American entomologist Dr. Justin Schmidt, who created the insect sting pain index, rated the bullet ant sting as the most painful sting in the world.

' Bullet ant stings can be painful for up to 12 hours and it's a deep, bone-chilling pain accompanied by sweating and goose bumps , quite unlike the 10-minute effects of a typical bee sting,' said lead author Sam Robinson.

In the new study, scientists discovered that the toxin specifically targets the sodium channels of nerve cells.

'We discovered that the ant's venom targets the nerve cells that send our pain signals,' said Mr Robinson.

Normally, the sodium channels in these sensory neurons only open briefly in response to a stimulus. The ant toxin binds to the sodium channels and causes them to open more easily, and stay open and active, which results in a longer lasting pain signal.'

These sodium channel-targeting neurotoxins are unique to ants, Robinson added.

This discovery helps researchers better understand how pain works and how to treat it.