Dave: The bails are horizontal.
Little Hawk: The batting team are 'in' until they have lost 10 players, at which time they can no longer man both ends of the wicket. This upsets statistics, as there is always one player who can rack up a score without being given as 'out'.
Batsmen can also be 'run out' where the ball is put, or thrown, to dislodge the bails whilst they are running between ends. They are considered 'safe' once they, or the bay they hold, touches the ground behind the 'batting crease' (the mark in front of the stumps at which they stand to await the ball.