Hush, don't mess with the ants!

Before the ants dig the tunnel, the force chains between the particles in the soil are arranged randomly (left), but when the ants dig the tunnel, the force chains are rearranged
.

The researcher is standing next to the ant nest model
.

But when Lucas was shrunk by the magic potion and came below the surface, a magical underground kingdom of ants appeared in front of him
.

Now, using X imaging and computer simulations, American researchers have uncovered how ants build these complex and stable structures
.

Do it only if you want

Do ants "know" how to dig tunnels, or do they just dig blindly? José Andrade of California Institute of Technology has always had this question
.

But Andrade was an engineer and knew nothing about ants, so he turned to Joe Parker, an assistant professor of biology and bioengineering at the school, whose research focused on ants and their ecological relationships with other species
.

Parker said: "The Andrade team needs a person who studies ants to understand the adaptability and collective behavior of these social insects and provide some biological information to clarify the mechanism of their mining behavior
.

"China Science News" learned from the California Institute of Technology that researchers spent nearly a year cultivating ants and understanding them
.

The researchers established a small colony in a container with 500 milliliters of soil and 15 western worker ants
.

"The ants are a bit capricious.
They dig when they want to dig
.

But once the ants start to act, the researchers will perform X-ray scans of the entire process to generate 3D scans of all internal tunnels
.

Ants also understand physics

Next, the researchers began to analyze what the actual work of the ants was
.

They found that, first of all, the ants would improve their efficiency as much as possible, they would dig along the inner edge of the container, because the container itself can act as part of the tunnel structure, thereby reducing the workload
.

They also dug the tunnel as straight as possible
.
"Because a straight line is the shortest path between two points
.
Moreover, they know how to use the sides of the container, which shows that the ants work very efficiently
.
" Andrade said
.

The ants will also dig as steep tunnels as possible until they reach the so-called angle of repose
.
This angle represents the maximum angle at which the granular material can accumulate before collapsing
.

What is the angle of repose? Andrade mentioned that imagine building a sand castle on the beach
.
If dry sand is used, every spoonful of sand added will slide down the piled sand
.
More sand will make the pile taller and wider, but it will never become steeper
.
On the other hand, if the use of wet sand, the sand will be able to get steep enough to build walls, towers and sandcastles etc
.

Wet sand has a higher angle of repose than dry sand, and ants can tell how steep the angle can be when digging a hole, and it will not exceed this angle
.
"If I am a digger and I want to survive, my digging technique must conform to the laws of physics, otherwise the tunnel will collapse and I will die
.
" He said
.

Finally, the physical principle of the ant tunnel is this: when the ants remove the soil particles, they will cause the gravity chain to rearrange around the tunnel
.
These power chains are random before the ants start to dig
.
After the rearrangement, the force chain strengthened the existing soil wall of the tunnel on the one hand, and at the same time reduced the pressure on the particles at the end of the tunnel, making it easier for the ants to remove them safely
.

"In engineering and ant ecology, how ants build these decades-long structures has always been a mystery
.
" Parker said, "It turns out that ants benefit from these circular force chains when they dig
.
"

Super organism

Back to the question at the beginning: Do ants know what they are doing when they dig?

In fact, someone once poured molten plastic or metal into an ant nest and solidified into a model, and then people could see these huge tunnel systems
.
"These systems are impressive
.
I once saw a photo of a model with a person next to the model, and I thought,'Oh my God, this is a wonderful structure
.
' Since then, I began to wonder whether the ants'know' how.
Dig
.
" Andrade said
.

However, there is no way for people to question the ants, so the researchers assumed from the beginning that the ants consciously fumble in the soil, looking for loose soil particles to remove
.
This is like a game of drawing blocks.
Players need to choose which block can be safely taken out
.
The stones that cannot be removed are part of the load-bearing "beams" (ie, the chain of force) of the ant building
.

"In the beginning, we assumed that the ants could feel these force chains and avoid digging there
.
They may be beating the soil particles continuously to assess the mechanical force exerted on these particles
.
" Andrade told reporters, "but then, We found that they don’t seem to “know” what
they’re doing .
They don’t systematically look for weak spots in the sand
.
Instead, they may have evolved their digging capabilities based on the laws of physics
.
”

Parker calls this a behavioral algorithm
.
"This kind of algorithm does not exist on an ant
.
" He said, "All worker ants' group behavior is like a super organism
.
How this behavioral program is spread in the small brains of all these ants is natural.
A miracle, we cannot explain it
.
"

Andrade hopes to develop an artificial intelligence method that can simulate this behavioral algorithm, so that he can simulate how ants dig on a computer and use the ants' digging capabilities to build human tunnels
.

"Compared with materials such as fluids or solids, granular materials are formed in different ways
.
Moreover, moving granular materials is very energy-consuming and costly
.
" He said, "If the ant's behavior algorithm can be further analyzed and finally Copy, then it may be applied to automatic mining robots, whether on the earth or on other planets, the robots can work more efficiently
.
"

So, don't mess with ants
.
(Source: Tang Feng, China Science News)

Related paper information: https://doi.
org/10.
1073/pnas.
2102267118