Scientists Discover an Entirely New Form of 3D Vision in Praying Mantises
Praying mantises have a talent that no other insect with compound eyes can perform. While bees and ants and flies are all able to see a wide angle on the world thanks to their compound eyes, they're unable to see in 3D, which means that they have no depth perception.
Scientists at the University of Newcastle in the UK have been experimenting with praying mantises to learn how much their depth perception allows them to see. In order to do this, they've been putting adorable tiny 3D glasses on the insects, and then showing them 3D movies to figure out when they react.
These glasses aren't the bulky plastic things you might wear when going to see a James Cameron film, but are instead blobs of honey, which the scientists placed over the bugs' eyes in order to allow them to perceive a 3D visual display on a 2D screen.
The scientists then showed them videos of their prey animals, and watched to see what stimuli caused them to react. The results were fascinating: the mantises only responded to videos that showed their prey moving, and weren't fooled by still images of other bugs and creepy crawlies.
Here's a praying mantis wearing 3D glasses. What a time to be alive pic.twitter.com/nb5EjGg5P9— Patrick Galey (@patrickgaley) February 8, 2018
Apparently, praying mantises don't perceive depth in the same way as most other animals. Where mammals such as humans see in 3D based on the amount of light that reaches each of their separate eyes, mantises instead watch for movement, tracking motion in order to determine how far away something is. This actually allows them to see some 3D videos that don't make sense to the human eye.
According to lead scientist Vivek Nityananda, who said the following in a press statement:
The good news is that if you've ever had a nightmare about finding yourself face-to-face with a giant praying mantis (we've all been there), we now know the best way to trick this particular monster. Mantises apparently only see motion, like the T-Rex in Jurassic Park (a claim that is dubious in real life), so staying perfectly still would theoretically prevent any giant mantises from being able to see you.
It's probably for the best that humanity figures out this little nugget of wisdom before we learned how to enlarge killer insects.
In the meantime, we can all appreciate this intriguing insight into the way the praying mantis sees the world, and why it's among the coolest, most interesting creatures in the animal kingdom.