The disease known as rabies is caused by a virus, usually transmitted via fluid transfers (in this case, biting). However, the disease can also be transmitted by aerosol, eyes, nose, mouth, and even corneal transplants. It is a disease that can affect most warm-blooded animals, including humans, although it is most commonly found in animals such as raccoons, dogs, and bats. Most human cases are caused by attack by an infected animal exhibiting aggressive behavior unusual to the species.

When the virus first enters a host, it enters the bloodstream and moves to the nervous system. The virus will quickly multiply, although no symptoms will show during the initial incubation period, which can last anywhere from several days to several years. The virus first begins to produce major symptoms after reaching the brain, where it begins to affect the behavior of the host. Once the virus reaches the salivary glands, it will induce the production of large amounts of saliva, another obvious indication of rabies infection.

At first, the victim will feel pain at the site of the bite and a headache, as well as some other flu-like symptoms. Once the infection has entered the brain, the victim will start showing a wide variety of mental disorders, ranging from confusion and agitation to hallucinations and delirium. If rabies symptoms appear before treatment is received, there is little or no chance of survival. Before symptoms appear, the victim can be vaccinated or injected with passive antibodies.

The rabies virus itself is bullet-shaped and approximately 180 nanometers in length by 75 nanometers in width. It is an RNA virus and produces five different proteins after entering a host cell.

To prevent rabies infection, the best way is to avoid encounters with wild mammals. If you do encounter an animal that appears to be infected, run and notify local authorities. If you are bitten by any warm-blooded animal, it is a good idea to get a blood check to ensure that you aren't infected.