I found this on http://tech.slashdot.org/article.pl?sid=10/08/13/217237from www.economist.com
A single ant cannot do much on its own, but the colony as a whole solves complex problems such as building a sophisticated nest, maintaining it and filling it with food. That rang a bell with people like Marco Dorigo, who is now a researcher at the Free University of Brussels and was one of the founders of a field that has become known as swarm intelligence.
Dr Dorigo was interested to learn that ants are good at choosing the shortest possible route between a food source and their nest. This is reminiscent of a classic computational conundrum, the travelling-salesman problem. Given a list of cities and their distances apart, the salesman must find the shortest route needed to visit each city once. As the number of cities grows, the problem gets more complicated. A computer trying to solve it will take longer and longer, and suck in more and more processing power. The reason the travelling-salesman problem is so interesting is that many other complex problems, including designing silicon chips and assembling DNA sequences, ultimately come down to a modified version of it.Read more at www.economist.com