Ants Form Rafts to Protect Queen, but Use Young Ones On Bottom to Maximize Buoyancy
ByIn the event of a flood, ants will use their young to place on the bottom of a raft they build with their own bodies, which is also an effort to save the queen.
According to the Los Angeles Times, a new study, published in the journal PLOS One, examined these rafts and how their structure maximizes buoyancy. However, this requires the youngest ants to be on bottom and therefore putting them at risk to drown or be fed to fish.
"It was an interesting contribution. No one had really looked at this idea of the brood as a flotation device," David Hu, a mechanical engineer at the Georgia Institute of Technology not involved in the study, told the LAT. "It adds a level of sophistication to the rafts that was previously not understood."
Like bees and termites, ants are social animals that work together to solve problems. Their incredible organizational skills are also known as "swarm intelligence," which means the colony knows how to swiftly respond to certain situations.
For their study, the researchers gathered a group of ants including workers, brood ants and queens, who are the mothers of their colony. The hypothesized that the brood ants (the vulnerable young ones) and the queen would receive special treatment and the workers would place them toward the center of the raft.
In groups of 60 workers, 10 broods and one queen, the workers actually used the younger ants at the bottom and did place the queen toward the middle. Compared to a group with only adult ants, the first group's raft floated much more effectively.
"We expected that individuals submerged on the base of the raft would face the highest cost, so we were astonished to see the ants systematically place the youngest colony members in that positions," study lead author Jessica Purcell, of the University of Lausanne, Switzerland, said in a press release. "Further experiments revealed that the brood are the most buoyant members of the society and that rafting does not decrease their survival; thus, this configuration benefits the group at minimal cost."