The ark was Noah's escape from the flood. Winnie-the-Pooh had an umbrella. Fire ants form floating rafts made of thousands or even hundreds of thousands of individual insects.
A new study by engineers at the University of Colorado Boulder lays out the simple physics-based rules that govern how ant rafts grow over time. One day researchers will be able to design robots that work together in swarms or next-generation materials in which molecule migrate to fix damaged spots.
The results were published in a journal.
The origin of such behaviors lie in fairly simple rules, according to the primary investigator on the new study.
These giant floating blobs of wriggling insects are formed by fire ants after storms in the southeastern United States.
Vernerey and Robert Wagner used mathematical simulations to try to figure out the mechanics of the lifeboats. They discovered that if the ants in a raft move fast, the rafts will expand outward.
The behavior could occur spontaneously, according to a graduate student in mechanical engineering.
Treadmill time.
The secrets of ant rafts were discovered by the two men.
In a study published in 2021, the duo dropped thousands of fire ants into a bucket of water with a plastic rod in the middle. They waited.
We left them in there for up to eight hours to observe the evolution of the rafts.
The structures would draw in to form dense circles of ants rather than staying the same shape over time. The insects would fan out like pancake batter on a skillet at other points.
The group reported that the ants seemed to modify their shape through a process called "treadmilling." There are ants who cling to each other and make up the base on the bottom. A second layer of ants walk around on top of each other.
During a period of time, ants from the bottom may crawl up to the top, while free-roaming ants will drop down to become part of the structural layer.
The whole thing is a doughnut-shaped treadmill.
The bridge to safety.
He and Vernerey wanted to find out what makes that treadmill work.
The team created models that turned an ant raft into a complicated game of checkers. Roughly 2,000 round particles were programmed by the researchers to stand in for the ants. The agents were not allowed to make their own decisions, but they did follow a set of rules, such as not bumping into their neighbors, and trying to avoid falling into the water.
When the game was over, the simulation ant rafts behaved like the real thing.
The team was able to figure out if the individual ants were slow or active in their simulations. The longer the ants walked, the more likely they were to form long extensions that stuck out from the raft.
He said that the ants at the tips of the protrusions almost get pushed off of the edge into the water.
Fire ants use these extensions to look for logs or other bits of dry land.
The researchers still have a lot to learn about ant rafts, for example, what makes ants in the real world switch from being sleepy to lazy. Vernerey says that engineers could learn a thing or two from fire ants.
Our work on fire ants will hopefully help us understand how simple rules can be programmed, such as through a system that dictates howrobots interact with others, to achieve a well-targeted and intelligent swarm response.
More information: Robert J. Wagner et al, Computational exploration of treadmilling and protrusion growth observed in fire ant rafts, PLOS Computational Biology (2022). DOI: 10.1371/journal.pcbi.1009869The Journal of The Royal Society Interface is about treadmilling and dynamic protrusions in fire ant rafts. There is a DOI: 10.1098/rsif.
Citation: The physics of fire ant rafts could help engineers design swarming robots (2022, March 2) retrieved 2 March 2022 from https://phys.org/news/2022-03-physics-ant-rafts-swarming-robots.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
All Rights Reserved © 2024
