What the Praying Mantis Teaches Us (Apart from Humility)

By Shlomo  Maital   

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    The praying mantis is an incredible insect, able to snatch flies and mosquitos out of the air. Like a sophisticated anti-missile rocket, it uses its superb vision like radar to locate its prey, then leaps to intercept it with stunning accuracy.  It turns out that humans can learn a lot from the praying mantis, and from the owl, chameleon, and the pigeon, beyond just humility (all those creatures, with tiny brains, see far far better than we humans do). 

    Caltech Jet Propulsion Laboratory expert Yoseph Bar-Cohen said, at a 2005 conference, “After billions of years of evolution, Nature has learned what works and what would last.”  Survival of the fittest has given praying mantises superb vision so they can snatch flies and mosquitoes out of the air; otherwise, they starve.  Natural selection has given similarly sharp eyes to chameleons, owls and pigeons.  

   Learning from Nature is a large and growing field called “biomimetics”, which means imitating Nature.   Need tough cable?  You could use steel threads. But it is far better to use spider silk, which has tensile strength twice as high as steel.  

   The most famous biomimetic invention is Velcro.  In the late 1940s,  a Swiss engineer, George de Mestral, took his dog for a walk.  As happens to many of us dog lovers, he noticed cockleburs sticking to his dog’s fur.  He analyzed the  tiny hooks that stick the seed-bearing burs to the dog’s coat and by 1955 had patented Velcro, a fastener with hooks on one side and soft loops on the other. 

    I visited Technion Computer Science Prof. Ehud Rivlin’s machine vision lab, where praying mantises, owls, pigeons, and chameleons are studied to learn the secrets of their keen vision.  Prof. Rivlin is an expert on robotic machine vision.   Helping robots see better, it turns out, is a key part of improving how they function.   Over 20 years ago,  Rivlin embarked on a risky and challenging research project, to better understand vision by studying creatures who see far better than humans.   His quest brought him to study birds, insects and lizards. His goal: Make robots that can see much better.  And he and his collaborators have succeeded.  They have quantified the praying mantis’ method for tracking prey mathematically, built a compute algorithm based on it and then created a praying mantis head ‘camera’ that replicates how the mantis sees.

    How does the mantis do it?  Why is the praying mantis so good at catching its prey? In a 2003 paper Rivlin and his student Igor Katsman (who is now launching a startup) found that it likes to move its head from side to side (a technique known as ‘peering’, also giving it its name, because peering resembles praying). This creates “motion parallax”,  a way to judge depth by the intersection of two different sight lines. 

  Two decades ago, Prof. Rivlin undertook a highly risky research program, linking computer science with biology, driven by, as he told me, three things: curiosity, desire to change the world, and the drive to show ‘feasibility’ (insect vision can be incorporated in robots).  I hope Rivlin’s story will inspire young researchers to undertake similarly risky interdisciplinary studies.