I'm addicted to these stories of parasites controlling their hosts. Were we less fussy when we carried worms? Is OCD (obsessive compulsive disorder) an adaptive response to the lassitude and carelessness worms create? (In other words, OCD is the disorder that emerges when the worms are gone, when the worms are present the same neurologic structures counteract the worm effect).
The big focus now is on Toxoplasma. How does this lovely litte brain infesting critter change our behavior? What's the curious relationship to some schizophrenia-like conditions? Carl Zimmer, one of our best science writers, summarizes the stor to date: The Return of the Puppet Masters.
Parasites are cool.