From The National Geographic:
The parasite Toxoplasma gondii uses a remarkable trick to spread from rodents to cats: It alters the brains of infected rats and mice so that they become attracted to—rather than repelled by—the scent of their predators. A new study reveals that rodents infected with the parasitic protozoa are drawn to the smell of cat urine, apparently having lost their otherwise natural aversion to the scent. The parasite can only sexually reproduce in the feline gut, so it’s advantageous for it to get from a rodent into a cat—if necessary, by helping the latter eat the former.
Toxoplasma-infected mice and rats retained most typical rodent phobias, including fears of dog odors, strange-smelling foods, and open spaces. Infected rodents also didn’t appear to be sick. Only the animals’ response to cats was abnormal: Uninfected rodents avoided an area of a room that researchers had scented with cat urine. But infected rodents actually seemed drawn to the smell. “Toxoplasma affects fear of cat odors with almost surgical precision,” Vyas concluded. “A large number of other behaviors remain intact.”
More here.
