Treadmill time
Wagner and Vernerey found the secrets of ant rafts nearly by mishap.
In a separate research study released in 2021, the duo dropped thousands of fire ants into a bucket of water with a plastic rod in the middle– like an only reed in the middle of stormy waters. Then they waited.
” We left them in there for up to 8 hours to observe the long-term development of these rafts,” Wagner said. “What we ended up seeing is that the rafts started forming these developments.”
In this timelapse footage, scientists catch a fire ant raft changing from a spread-out state with long protrusions to a more compact form. Credit: Warner and Vernerey, PLOS Computational Biology, 2022
Rather than remain the very same shape with time, the structures would compress, drawing in to form thick circles of ants. At other points, the insects would fan out like pancake batter on a frying pan, even developing bridge-like extensions.
The group reported that the ants appeared to regulate these shape changes through a procedure of “treadmilling.” As Wagner described, every ant raft is comprised of two layers. On the bottom, you can discover “structural” ants who stick tight to each other and make up the base. Above them are a second layer of ants who walk easily on top of their fellow colony-members.
Over a period of hours, ants from the bottom may crawl as much as the top, while free-roaming ants will drop down to become part of the structural layer.
” The whole thing resembles a donut-shaped treadmill,” Wagner stated.
Engineers at CU Boulder established computer simulations to attempt to recreate the characteristics of fire ant rafts. Blue dots represent ants at the bottom of the raft, and red dots are ants walking around easily on top of the raft. Credit: Warner and Vernerey, PLOS Computational Biology, 2022
Bridge to safety
In the new study, he and Vernerey wished to explore what makes that treadmill go round.
To do that, the team created a series of models that, essentially, turned an ant raft into a complicated game of checkers. The researchers configured approximately 2,000 round particles, or “agents,” to stand in for the ants. These representatives could not make choices for themselves, but they did follow an easy set of guidelines: The fake ants, for example, didnt like bumping into their next-door neighbors, and they tried to avoid falling into the water.
When they let the game play out, Wagner and Vernerey found their simulated ant rafts behaved a lot like the real things.
Fire ants form an ant raft. Credit: Vernerey Researcher Group at CU Boulder
In particular, the team was able to tune how active the representatives in their simulations were: Were the individual ants sluggish and lazy, or did they walk a lot? The more the ants strolled, the more likely they were to form long extensions that stood out from the raft– a bit like individuals funneling toward an exit in a congested arena.
” The ants at the suggestions of these protrusions nearly get pressed off of the edge into the water, which results in a runaway effect,” he said.
Wagner believes fire ants utilize these extensions to probe their environments, looking for logs or other little bits of dry land.
The researchers still have a lot to discover ant rafts: What makes ants in the real life, for example, opt to change from sedate to lazy? For now, Vernerey states engineers could learn a thing or 2 from fire ants.
” Our deal with fire ants will, ideally, help us comprehend how easy rules can be configured, such as through algorithms determining how robotics interact with others, to accomplish a well-targeted and smart swarm reaction,” he said.
Reference: “Computational expedition of treadmilling and protrusion growth observed in fire ant rafts” by Robert J. Wagner and Franck J. Vernerey, 17 February 2022, PLoS Computational Biology.DOI: 10.1371/ journal.pcbi.1009869.
Fire ants survive floods by forming rafts made up of thousands of wriggling pests. New research reveals how these creepy-crawly lifeboats alter shape in time.
Noah rode out his flood in an ark. Winnie-the-Pooh had an upside-down umbrella. Fire ants (Solenopsis invicta), meanwhile, form floating rafts made up of thousands and even numerous thousands of private pests.
As Wagner discussed, every ant raft is made up of 2 layers. Engineers at CU Boulder developed computer system simulations to try to recreate the dynamics of fire ant rafts. Blue dots represent ants at the bottom of the raft, and red dots are ants walking around easily on top of the raft. To do that, the team created a series of designs that, basically, turned an ant raft into a complex video game of checkers.
A brand-new study by engineers at CU Boulder sets out the simple physics-based guidelines that govern how these ant rafts change over time: shrinking, expanding or growing long protrusions like an elephants trunk. The teams findings could one day aid researchers design robotics that work together in swarms or next-generation materials in which particles move to repair damaged spots.
The results were released just recently in the journal PLOS Computational Biology.
Fire ants form a protrusion from an ant raft. Credit: Vernerey Researcher Group at CU Boulder
” The origins of such habits lie in relatively simple guidelines,” stated Franck Vernerey, primary detective on the brand-new study and teacher in the Paul M. Rady Department of Mechanical Engineering. “Single ants are not as clever as one may believe, but, jointly, they become really smart and durable communities.”
Fire ants form these giant drifting blobs of wriggling pests after storms in the southeastern United States to make it through raging waters.
In their latest study, Vernerey and lead author Robert Wagner made use of mathematical simulations, or designs, to attempt to find out the mechanics underlying these lifeboats. They found, for example, that the quicker the ants in a raft relocation, the more those rafts will expand outside, often forming long protrusions.
” This behavior could, essentially, happen spontaneously,” stated Wagner, a graduate trainee in mechanical engineering. “There does not necessarily require to be any main decision-making by the ants.”
Fire ants (Solenopsis invicta), meanwhile, form drifting rafts made up of thousands or even hundreds of thousands of private pests.