This set of activities lets you play with Langton's ants, that are 2D turing machines. They constitute very simple application problems, achievable by beginners, and open the door to an amazing world.
This mechanism were invented in 1986 by Chris Langton, and later generalized in several ways (as we shall see in the next exercises). It was proven that Turmites and Turing machines are of equal power: An ant's trajectory can be used to compute any boolean circuit, and thus that an ant is capable of universal computation. Put simply, any possible computation can be achieved using a turmite as a computing device. Yet another subject of fascination...
Multicolor Langton's ants were discovered in 1995 by Propp et Al. Another funny fact is that the ants which name is a list of consecutive pair of identical letters (LL and RR) produce symmetric patterns. This fact was even formally proved.
Check the corresponding wikipedia web page, of which this exercise is inspired, for further details.
As usual, there are several things that could be done in the code of this universe to improve it: