Praying mantises are the only invertebrates known to see in 3D. Unlike us, their depth perception only works when the object – prey – is moving. Humans see in 3D by stitching together the actual image coming in from one eye versus the other, but the actual image doesn’t matter to mantises. Their depth perception only focuses on things that are changing. The mantises were able to see changes in the world that human eyes were incapable of picking out.


According to recent researches, mantises each eye could see completely different scenes. As long as both eyes could see something that looked like prey, and that prey was moving, the mantis could still judge the distance to it. That’s different from how it works for us, where pretty much all the details need to match up. If one eye was seeing a forest and the other a building, for example, it wouldn’t matter if an object was moving in similar spots on both scenes, we still wouldn’t be able to tell how far away it was.

I think that same efficiency from mantises’ stereoscopic vision mechanism could help robots like drones judge distance or could design a mantis-inspired machine vision.