Well actually they're more like a Beauveria-humanoid symbiosis. Beauveria is an asexually reproducing form of Cordyceps that causes a white "mold" to grow on its hosts, rather than the distinctive sexual Cordyceps stalk. If you have ever seen a fruit fly die on your kitchen window and left it there long enough for it to grow white stuff, there's a good chance you've seen the fly-infecting version. Like the sexual Cordyceps, Beauveria also makes its hosts more attracted to public places where its spores are more likely to spread to other hosts.