Natures wonders: ant rafts have set crews! (Introduction)

by David Turell , Tuesday, April 19, 2016, 00:01 (3139 days ago) @ David Turell

It seems the same ones occupy the same positions when the raft is formed:-"The team of scientists, including Jessica Purcell, an assistant professor of entomology at The University of California, Riverside, focused on Formica selysi, an ant species found in floodplains in central and southern Europe.-"A team of scientists has found that a species of ant that clusters together to form rafts to survive floods exhibits memory and repeatedly occupies the same position during raft formation, according to a just published paper. -"The research shows that, like humans, ants work together to enhance their response to emergency situations with different members of the group carrying out different tasks.-"By working together, social insects, such as ants, achieve tasks that are beyond the reach of single individuals. A striking example is "self-assembly," a process in which ants link their bodies to form structures such as chains, ladders, walls or rafts.-***-"In a lab, they subjected groups of Formica selysi workers to two consecutive floods and monitored the position of individuals in rafts. Workers showed specialization in their positions when rafting, with the same individuals consistently occupying the top, middle, base or side position in the raft.-"In addition, they found the presence of brood, or immature members of the ant society, modified workers' position and raft shape. Surprisingly, they found workers' experience in the first rafting trial with brood influenced their behavior and raft shape in the subsequent trial without brood.-"They believe this is the first time memory has been demonstrated in so-called self-assemblages."-Comment: If they all know where to place themselves, it smells like instinct to me. It makes no sense they practiced their positions in advance of getting hit with a flood. By living in a flood prone area, I'm sure the instinct developed by necesity.