http://www.medicaldaily.com/toxoplas...illness-337030
Revisited. About 22.5% of the US has this brain parasite, other parts of the world are much closer to 100%.
Has been known to slow response times in humans, and other very strange effects, including - hoarding of cats. Causes extroversion in human females and introversion in human males.
Has been tested in mice and will actually cause mice to be sexually attracted to cat urine.