Praying mantises are the only insects that can see in 3D, but scientists have just discovered that their vision works completely differently to ours – and all other forms of 3D vision found in nature.
Researchers from the neuroscience department of Newcastle University used beeswax to strap 3D glasses on to 20 praying mantises, and then set them up with their own personal cinemas.
They played the insects videos of moving dots just a couple of centimetres from them, which they mistook for prey and launched for, and could even spot the moving dots in circumstances that would confuse most humans.
Human 3D sight, or stereo vision, works because our eyes are able to merge the views we get from both eyes into one image for our brains to process and tell how far away things are.
But these scientists found that praying mantises don’t see like this.
Instead, their 3D vision only helps them tell the difference between moving and stationary images.
Praying mantises don’t need to be able to tell the difference between still images either, as they only hunt moving prey.
Using the 3D glasses to manipulate what the praying mantises saw through each eye, even when the images going to the insects’ two eyes were different, they could still spot the movement, which is something even humans struggle to do.
But what are the real-world applications of putting cinema goggles on praying mantises?
It could help us create robots with stereo vision in a way we’ve never tried before.
“Many robots use stereo vision to help them navigate, but this is usually based on complex human stereo,” said Dr Ghaith Tarawneh, of Newcastle’s engineering department.
“Since insect brains are so tiny, their form of stereo vision can’t require much computer processing. This means it could find useful applications in low-power autonomous robots.”
The paper was published in the journal Current Biology and can be read here.