One player sits on the ground and is blindfolded. Tennis balls are then spread around them (try to have about 5 per playparticipating player) Players then take it in turns to try to sneak up and grab a tennis ball. The blindfolded player must try to stop them. If the blindfolded player touches a player, the ball is put back, otherwise the player puts the ball in their pile. Once all the balls have been taken, the player with the least balls in their pile becomes the next blindfolded player.
Source: From the original site.