A vector is an organism, typically a biting insect or tick, that transmits a disease or parasite from one animal or plant to another. An example of a vector in biology is the mosquito, which carries the virus that causes malaria. Another example of an insect vector is the tsetse fly, which carries trypanosomes from animals to human beings. Animals such as dogs and bats can sometimes be referred to as vectors since their bite may cause transmission of viruses that cause rabies.
