Zoonoses or zoonotic diseases are those which can be transmitted directly from animals to humans, infection that can be acquired indirectly from the environment by humans from animals, and diseases which have an animal reservoir, but require an arthropod (insect, mite, or tick) to transmit the disease to humans. Zoonoses or zoonotic diseases are all the diseases collectively as described above. A single disease, such as rabies, is called a zoonosis or zoonotic disease.