Langton's Anthill is a 2-dimensional cellular automaton based on Langton's Ant.But instead of the original two states (on/off, alive/dead), cell on the anthill have 255 states. Accordingly, the ants follow a list of 255 left/right rules. Every ant has a randomly generated, more or less unique set of rules it follows while hopping from cell to cell.
In the simulation the state of each cell is represented by a shade of grey where white represents the state 0 and black the state 255. If a cell has state 255 and gets increased once more it flips to state 0.