Why do cockroaches like to hit the wall?

The way cockroaches climb walls may seem unorthodox, but it gives them a great advantage in the vertical direction. (photo: ooKIRATHIKANoo/Shutterstock)

It's usually not a good thing to tie a wall, but it seems to be very useful for cockroaches.

A study published in the Journal of Interface of the Royal Society found that these insects entered the wall in this way in order to reflect their bodies from one angle. This enables them to climb the vertical surface without any difficulty.

This is a cunning escape strategy, which scientists believe will help them develop better robots.

On the wall

American cockroaches are very fast, moving at a speed of 50 body lengths per second. When competing on the floor to avoid predators, cockroaches may aim at the wall and move forward. Such a collision should be able to stun insects, but they have a shock-absorbing body, which not only protects them from harm, but also allows them to guide this force to really climb the wall.

The researchers asked 18 male cockroaches to run on the surface of the paper lining. They shoot high-speed video at 500 frames per second and use some motion tracking software to see how these errors appear on the wall. Both of them are important, because to the naked eye, cockroaches seem to climb the wall without missing a step. It seems that they can easily change from horizontal scribing to vertical scribing.

However, once the researchers observed the camera, they found that the cockroach would rather hit the wall with its head, absorb its strength, bounce back to the climbing angle and continue to rush forward. Use this method 80% of the time. The rest of the time, the cockroach will tilt up a little before hitting the wall, slowing down the attack speed.

Caution is usually unnecessary. The researchers found that those cockroaches that hit the wall made vertical movements at the fastest speed of about 75 milliseconds-just like those cockroaches that showed a little caution. However, considering that they don't slow down when they collide with the wall, this gives cockroaches a greater chance to escape predators, which can make a huge difference in their survival.

"Their bodies are doing calculations, not brains or complex sensors," Kaushik Jayaram, a biologist at Harvard University and the lead author of the study, told The New York Times.

A better robot

In order to determine whether this method will be transformed into a robot to help them navigate difficult terrain, Jayaram and the research team built a small palm-sized hexapod robot called DASH, which has no sensors in front. Robots will rely on their bodies to navigate like cockroaches. The researchers added a tilted cone named "nose" to promote any potential upward tilt that the robot may achieve. Shoot robots like cockroaches.

DASH tries to make a vertical transition, just like a cockroach. In the next iteration of DASH, the team hopes to add a "substrate attachment mechanism" so that it can climb the wall after the transition movement.

Researchers believe that their method is a "paradigm shift" in robotics and a new method for manufacturing robots. By relying on more mechanical-based methods than sensor-based methods, robots can be more powerful and explore difficult areas more easily.