Swarm Intelligence

increases. A termite approaching the area then detects the pheromone,

and as there are multiple pillars and the termite is steering toward the

highest concentration, it is likely to end up in the area between two pil-

lars. It is attracted toward both, and eventually chooses one or the other.

As it is approaching the pillar from the region in between, it is more

likely to climb up the side of the pillar that faces the other one. As a con-

sequence, deposits tend to be on the inner face of the pillars, and as each

builds up with more substance on the facing side, the higher it goes the

more it leans toward the other. The result is an arch.

Termite builders ...