A strange illness called chronic wasting disease— or "zombie deer disease" — is on the move. Officials in several US states are issuing warnings.
Currently, the disease is found in animals like deer, elk, and moose. It can take up to two years before signs of CWD become visible. At some point, though, the illness will cause an infected deer to lose weight, stop interacting with other deer, and lose its fear of humans. The animal winds up staring vacantly as it starves to death.