Insects have a unique way of keeping their fangs sharp, research finds

Ant mandibles pack a powerful bite, thanks to embedded atoms of zinc (University of Oregon/SWNS)
Ant mandibles pack a powerful bite, thanks to embedded atoms of zinc (University of Oregon/SWNS)

Anyone unlucky enough to have been bitten by ants knows they pack a punch for an insect so small.

It turns out that ants, spiders and other creepy crawlies actually have a unique way of keeping their fangs sharp.

Their ‘pincers’ are covered in zinc atoms which are specially arranged to maximise cutting abilities and sharpness, according to a new study.

Many insects like ants, worms, spiders, have sharp teeth which allows them to slice, puncture, or sting without working too hard.

But how these tiny creatures keep their tools in working order so they can continue to cut and puncture with ease has remained a mystery.

Now, researchers at the University of Oregon in Canada have revealed nature’s solution to the problem.

Author Dr Robert Schofield said: ‘Human engineers might also learn from this biological trick.

‘The hardness of ant teeth, for example, increases from about the hardness of plastic to the hardness of aluminium when the zinc is added.

‘While there are much harder engineering materials, they are often more brittle.’

Ants’ teeth, which are technically called ‘mandibular teeth’ because they are outside their mouths, are made of different materials at a microscopic level.

Techniques to measure the materials abilities on a miniature scale had been developed by the researchers, but unfortunately they could not see them.

A specialised technique called atom probe tomography was therefore called upon to take a tiny needle sample from the tip of the ant tooth.

It was then imaged so the team could identify how individual atoms are arranged at the tip.

**EMBARGOED FOR RELEASE: 1-SEP-2021 05:00 ET (1-SEP-2021 09:00 GMT/UTC)** Arun Devaraj at work in the lab. See SWNS story SWNNinsects; How insects like ants and spiders keep their fangs sharp has been revealed, scientists say. Their ???pincers??? are covered in zinc atoms which are specially arranged to maximise cutting abilities and sharpness, according to a new study. Many insects like ants, worms, spiders, have sharp teeth which allows them to slice, puncture, or sting without working too hard.
Arun Devaraj from the US Department of Energy at work in the lab. (Credits: Pacific Northwest National / SWNS)

Co-author Dr Arun Devaraj at the United States Department of Energy said: ‘We could see that the zinc is uniformly distributed in the tooth, which was a surprise.

‘We were expecting the zinc to be clustered in nano-nodules.’

This natural sharpener means insects use 60 per cent less force than if their teeth were made of material found in human teeth.

It also means they use far less energy, which explains why so many other groups of organisms have these specialised tools, the researchers say.

The researchers are planning on taking a closer look at other materials to better understand what makes them stronger.

Dr Devaraj said: ‘By studying steel microstructure also at the atomic scale, we can better understand how altering the composition of materials changes its damage resistance, specifically stress corrosion resistance and behaviour over time.

‘This is especially important for designing structures like nuclear power plants that need to withstand ageing for many decades.’

The findings were published in the Nature journal Scientific Reports.

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