Forget GPS. With no fancy maps or even brains, immune system cells can solve a simple version of the traveling-salesman problem, a computational conundrum that has vexed mathematicians for decades.

With neither minds nor maps- chemical-sensing immune players do well with decades-old mathematical problem, a computer simulation reveals.

The travelling salesman problem as applied to ants in an ant colony. The ants initially lay down a path (1) but wind up exploring a myriad of possible interconnected paths (2) over time.

In this paper, we present a heuristic for the traveling salesman location problem on a network. Each day the salesman (e.g., a repair vehicle) must visit all the calls that are registered in a service ...