Vector species are organisms that carry and transmit pathogens, such as viruses or bacteria, from one host to another. Common examples include mosquitoes, ticks, and fleas. These species do not usually cause disease themselves but play a crucial role in the life cycle of the pathogens they carry. The transmission process often occurs when a vector feeds on a host, introducing the pathogen into the host's body. This can lead to various diseases, such as malaria from mosquitoes or Lyme disease from ticks. Understanding vector species is essential for controlling disease outbreaks and protecting public health.