Next time I go to the doctor, I think I’ll get him to give me a test for Toxoplasma. Fifty million Americans have the parasite, so I wouldn’t be the first. And if I was carrying it around in my head, that might explain why it’s so fascinating to me.

I first encountered the strange ways of this single-celled creature while working on my book Parasite Rex, and since then I’ve tried to keep up with new research on what makes it so successful. In January I wrote on the Loom about a potential link between Toxoplasma and schizophrenia.

In Tuesday’s New York Times I have an article that surveys some of the newest work on this bug–how, for