Illustrates a depth-first search of a maze. Click the green flag to start. The mouse checks possible directions with her pink nose, and moves right, forward, or left, if the path is clear. She leaves a trail of blue crumbs so she doesn't re-explore the same places. When she is done exploring a spot, she backs away from it and turns the crumb red.
Thanks to Cinda Heeren for suggestion and discussion of implementation.
