Press space to start/stop the ant. When the ant is not moving, you can draw the tiles yourself. The rules the ant follows are simple: If touching black, make that tile white, turn left, move one tile. If touching white, make that tile black, turn right, move one tile. Don't use turbo mode.
"Langton's ant is a two-dimensional Turing machine with a very simple set of rules but complex emergent behavior. It was invented by Chris Langton in 1986" -Wikipedia, https://en.wikipedia.org/wiki/Langton%27s_ant