A parade of so-called “zombie” rabbits sporting hornlike growths has sparked confusion and concern in Colorado. Wildlife officials say there’s no cause for alarm. These unusual creatures are simply living with a harmless,

W ildlife officials in Colorado are fielding calls about unusual sightings of cottontail rabbits with horn-like growths protruding from their faces. This condition, caused by a virus, is startling to see but not dangerous to people or pets.

The cottontail rabbit papillomavirus, which alarmed some Colorado residents, cannot spread to other species and often goes away on its own, according to experts.