The scientific name for fleas is Siphonaptera, which comes from the Greek words 'siphon', meaning pipe, and 'aptera', meaning wingless, relating to the sucking mouthparts and wingless condition of fleas.
Fleas are one of the best-known groups of parasitic insect due to their notoriety as pests and their medical and veterinary importance as vectors of disease, such as the plague, myxomatosis and murine typhus. They are holometabolous insects, meaning that they go through a metamorphosis of egg, larva, pupa and adult during their development.
The eggs are laid in the host nest, where the larvae develop as scavengers, feeding on detritus and flea faeces. The resulting pupae can remain dormant for some time, emerging as adults in response to vibration, heat and carbon dioxide, when a suitable host becomes available. Adults are obligate ectoparasites, with both males and females feeding on the blood of their mammalian/avian hosts. If the host dies, the decrease in body temperature prompts the adult flea to move onto a new host.