As reported in ScienceNews, an article in American Naturalist by Anderson et al (2009) documents the process by which fungus invades ants and turns them into zombies. http://www.sciencenews.org/view/generic/id/46184/title/Death-grip_fungus_made_me_do_it
The original article in AN:
Andersen, S. B., et al. 2009. The life of a dead ant: The expression of an adaptive extended phenotype. American Naturalist, 174, (September): 424-433.
As an aside, Dretske has been working on the question that plagues everyone ... "How do you know you are not a zombie." Of course, this puzzles me daily. Required reading.