Good Greyhounds stay steadfast to the cause and chase the robotic hare down the dirt track without asking any questions.
Smart Greyhounds decide that a real hare is better than the silicone variety.
From Victoria, Australia we have the tale of Ginny Lou who when given the choice showed the world she was in the latter category.
http://www.youtube.com/watch?v=X8UK-Hn5hMk&feature=player_embedded
By the way, Stewards annulled the race and returned 32,000 Australian dollars to people who had placed bets.