Via the mermaid’s tale:

Rats infected with the parasite Toxoplasma gondii do crazy things. They find the scent of cat urine sexy and attractive, they don’t run from the actual beasts; they are more active in running wheels, which might indicate that the parasite induces increased activity which may more readily attract a cat’s attention. When an infected rat is eaten by a cat, the T. gondii is passed on in the cat’s feces to infect again. T. gondii can only reproduce inside the cat. Great survival strategy on the part of the parasite, this trick of making the rat no longer fear cats — now that’s really building a better mouse-trap! Did this strategy evolve by adaptive selection, or is it just something that happened?

Czech biologist, Jaroslav Flegr, thinks T. gondii infections do much the same to humans — his story is told in the March 2012 Atlantic Monthly. Toxoplasmosis, the infection caused…