Animal viruses are viruses that infect animals. Viruses infect all cellular life and although viruses infect every animal, plant and protist species, each has their own specific range of viruses that often infect only that species. The viruses of vertebrates are informally distinguished between those that primarily cause infections of humans and those that infect other animals. Humans cannot be infected by plant or insect viruses, but they are susceptible to infections with viruses from other vertebrates. These are called viral zoonoses or zoonotic infections. For example rabies, yellow fever and pappataci fever.