"Five things you never knew about Pac-Man". Among the tidbits:

...[O]nly Blinky, the red ghost... doggedly pursues you throughout the game. Pinky, the pink ghost (naturally), simply wants to position itself at a point that's 32 pixels in front of Pac-Man's mouth. The blue ghost, Inky, is seeking to position itself at a similar fixed spot. And Clyde, the orange ghost, moves completely at random.

(Via GMSV.)