The surprising teamwork trick ants use to double their strength: the 'force ratchet'

New research has revealed that weaver ants have solved a teamwork problem that has plagued humans for centuries: laziness as the group grows. Unlike humans, when weaver ants work in larger teams, the effort expended by each individual increases rather than decreases. This strategy, called the "force ratchet," could inspire future robotics.

There's a rule of thumb known in the scientific world as the "Ringelmann Effect," proven since 1913: As human groups grow, the personal effort expended by individuals decreases. However, a new study published in the journal Current Biology shows that weaver ants completely break this rule.

"The pulling force of each ant almost doubled as the group grew, meaning they got better at working together as the group got larger," said Madelyne Stewardson, a behavioral ecologist at Macquarie University, summarizing their findings.

The secret of the ants' "force latch"

Weaver ants (Oecophylla smaragdina), which live in Africa, Asia, and Australia, are famous for building nests by pulling tree leaves together and binding them with silk produced by their larvae. When researchers studied the "living chains" these ants create as they pull the leaves, they discovered the secret to this incredible efficiency:

Division of Labor: The ants divide the task into two. Ants at the front of the chain actively pull the leaf, while those at the back act as an anchor, holding on tightly to the ground.

Force Storage: The "anchor" ants at the rear store the pulling force of those at the front, preventing the leaf from slipping back. This works like a ratchet mechanism. The longer the chain, the stronger the anchor and the stronger the pull the ants at the front can make.

Inspiration for future technology

This discovery not only offers fascinating insights into nature, but also holds groundbreaking potential for robotics.

One of the biggest limitations of current robot swarms is that they can only increase their force linearly when working as a team (e.g., 2 robots apply 2 times the force, 3 robots apply 3 times the force).

But according to Dr. Chris Reid, if robots are programmed to mimic the "force ratchet" strategy of weaver ants—some pulling while others act as anchors—autonomous robot teams could work much more efficiently and accomplish far more than the sum of their individual efforts. This could be a revolutionary development for autonomous construction or rescue robots in the future.