If you've ever owned a cat, chances are you've heard of toxoplasmosis, an infection caused by T. gondii, a single-celled parasite. The parasites enter the intermediate host's brain and muscle tissue and change its behavior in a way that boosts its chances of getting eaten by a cat. The mechanism isn't yet clear to researchers, but the phenomenon is most well known in rodents: Mice infected with T. gondii seem to lose their inherent fear of cats and no longer avoid the scent of cat urine, studies have shown. These daredevil mice make an easy meal for a cat, and in eating them, the newly infected feline unwittingly sets the process in motion once again. When it comes to evolutionary survival, T. gondii is optimized for cats and their prey, but other animals can get caught in the biochemical crossfire, with similar behavior-altering results. Even humans can be affected. Some behavioral changes—including taking risks in business, road rage, and even schizophrenia—may be associated with T. gondii infection. And now, a recent study in the journal Communications Biology has shown the first evidence of T. gondii's effect on gray wolves.

A wolf puts itself in danger when it leaves its family and goes off to join or form a new pack. Grey wolves infected with a mind-controlling parasite in Yellowstone National Park are taking greater risks, according to a study published in the journal Communications Biology. Scientists say a mind-controlling parasite is changing wolf behavior in Yellowstone National Park. Researchers discovered that grey wolves infected with Toxoplasma gondii were more likely to take risks. A new study showed infected wolves were 11 times more likely to leave the pack they were born into. Infected wolves were 46 times more likely to become pack leaders. Toxoplasma gondii relies on an acid found in the stomach of felines to reproduce. When the parasite infects a different animal, such as a wolf, it travels to the host's brain and muscles. The parasite changes the host's behavior in an effort to find its way back to a feline. The discovery in wolves could help scientists understand pack behavior and improve conservation efforts.