Why Is This Praying Mantis Wearing 3-D Glasses?

Looking into the eyes of the animal kingdom can teach us a lot about how we survive. The eye is an extraordinary part of our biological survival kit. From how it moves, to tracking other movement—when you study vision, you realize how much of what we’re seeing is an amazing creation of our nervous system. From gazing panoramically, to detecting color, and even seeing the invisible, new discoveries are changing the way we look at eyes in the animal kingdom. And once we know the structures, the question is how can we mimic them? And these breakthroughs could be crucial to our own species’ future survival.

Take for example one experiment led by Dr. Jenny Read and Dr. Vivek Nityananda that is studying the eyesight of one of the most successful predators in the world—the praying mantis—to see how this insect can pounce on prey with such lightning quick reflexes and pinpoint accuracy. They set out to answer the question, can the consummate animal killing-machine see 3-D like us?

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Vivek decided that the best way to find out was to take the insect to a 3-D action movie. But in order to see the movie, Vivek needed to first make some very, very tiny 3-D glasses for the praying mantis. After various attempts at getting the right material for the special glasses, the approach that seemed to work best was to use colored filters.

After a quick procedure using bee’s wax to attach the 3-D glasses and a device that holds the mantis in the stand for the experiment, the experiment was ready to begin. But how can they make sure the mantis is really seeing 3-D? Praying mantises will only strike at prey if they are close enough to their target. Jenny and Vivek make sure that the computer screen is out of the mantis’s strike range, but the 3-D target is within it. And if the mantis actually sees stereoscopically, it will strike at the 3-D target thinking it is close enough to go in for the kill.

Take a look at their experiment in action:

The obvious reason why a praying mantis would have evolved 3-D vision is for predation. If a prey comes within range, they’ll reach out and grab it very quickly, with a strike. Perhaps mantises have evolved a quick and dirty stereovision that’s not as good as ours, but does the job for them. And that is interesting not just from an evolutionary point of view, but perhaps it’s something researchers can harness to help humans.

Don’t miss an all-new episode of Explorer: Eyes Wide Open this Sunday at 8/7c with host Michael Stevens to explore the many ways that eyes help us and many other animals survive, and even how they inspire some incredible emerging technology.