The Super-Organism: The Beauty, Elegance and Strangeness of Insect Societies;
Ants and other social insects are good at what they do, and they get better by means of cooperative labor. Their behavior fulfills principles of ergonomic efficiency embodied in the Barlow-Proschan theorems. When individual competence is low, the first theorem says, the reliability of a system of individuals acting together is lower than the summed competence of the individuals acting singly; but when individual competence is high, above a certain threshold level, the reliability of the system based on cooperation is greater. According to the second theorem, one redundant system, whose parts that can be switched back and forth (as in colony members), is more reliable than two identical systems with no such backup parts.