Xenopsylla is a genus of fleasin the family Pulicidae. Many fleas, both male and female, transmit diseases and infections. They carry organisms that help transfer diseases to their hosts. Xenopsylla brasiliensis is the rat flea that can be found in Africa, India and Brasil. It is a transmitter of the plague. The fleas attack thier host and the arthropods host brings the diseases to humans through contact.