““Certain parasites in nature exert the kind of control that makes a host act contrary to its own interests. One protozoan, Toxoplasma gondii, reproduces inside the belly of a cat, and is then excreted by the feline. One way it begins the cycle again is to infect a rat passing near the excrement. Toxoplasma gondii reprograms the infected rat to love cat urine, which to healthy rats is a predator warning. An infected rat wallows in cat urine, offering itself up as an easy meal to a nearby cat. This way, the parasite again enters the cat’s stomach, reproduces, and is expelled in the cat’s excrement—and the cycle continues.””
