A turmite is a kind of 2D Turing machine. It has an internal state, and at each step, depending on its internal state and the color of the cell it is on, it puts a new color in the cell, moves in one direction (ahead, right, left), and picks a new internal state. The idea comes from the French version of "Scientific American", and I made a program on Amiga to simulate a bunch of them, with some reproduction and mutation rules.