Transformation to a “Clicker” is the result of a third stage infection with Cordyceps (Ophiocordyceps Unilateralis). The fungus is transmitted either by inhaling spores or from infected humans via body fluids. Growing in the human brain, it takes control of its host. Uncontrolled proliferation skews and scars the human face leading to complete blindness. Navigation just works via an adaptive echolocation generating the characteristic clicking noise.