Xenopsylla cheopis is the Latin name for the Oriental Rat Flea. It is theorized that the first flea was native to Africa and traveled by boat on the back of a rat from country to country. Fleas live off the blood of their hosts which allows them to spread deadly diseases such as the Bubonic Plague. The plague manifests itself in humans by causing swollen lymph nodes, high fever, and delirium. Antibiotics quickly cure the infection but left untreated, the plague will take on a pneumatic form and causes severe coughing and wheezing. If no medicine is administered, the patient will almost surely die. While not a true insect, fleas are arthropods, which are related.