Story of ants: how they build a raft from memory
Do ants rely on memory to work together? Apparently, yes.
A research group at the University of California, Riverside, showed that ants remember their positions within the ant-made rafts.
A species of ant, Formica selysi, found in floodplains of central and southern Europe, survive floods by forming a bodily cluster to build a raft. The process of ants linking their bodies to form a structure is known as self-assembly, and is an incredible example of cooperative behavior in social insects. These self-assembled structures come in different shapes: chains, ladders, walls, and — in the case of F. selysi — rafts.
The scientists tracked the positions of the ants within rafts by painting them in color-codes. They observed that the worker ants are specialized in their positions when forming a raft, consistently occupying the top, middle, base or side.
In the previous study, the same research group found that the workers put the most precious member of the colony, their queen, in the middle of the raft. You might be surprised, but the vulnerable brood were placed at the base of the raft. This takes advantage of the brood’s ability to float, making the raft sturdier and increasing the chance of survival for all, according to the scientists.
In case you were wondering, these ants are not the ones that carried Ant-Man afloat through a plumbing system in Marvel’s Ant-Man. The culprits are fire ants, belonging to the genus Solenopsis, which can also form rafts.