What are those zombies doing?!

Editor John Joseph Adams writes of his "Name-that-Zombie Caption Contest." The best caption of 50 or fewer words, describing the picture of zombies in this post, will win a copy of Adams's The Living Dead anthology and a copy of the new Xbox game Left 4 Dead. Captions, which should be posted as comments to that entry, are due by midnight (naturally) on Friday the 13th (of February).