Fleas are pests of humans and their domestic animals all over the world.
Flea larva feeds on organic debris and fecal blood. Adults fleas and ticks feed on human or other animal blood. Fleas transmit several diseases, such as plague and Murine Typhus. Fleas were responsible for the black plague that killed over 100 million people in the 14 century. The most common host is the domestic dog and it is virtually restricted to this host in the United States.