The northern rat flea is a species of flea

Flea

Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...

 that is found on domestic rats and house mice. Northern rat fleas are external parasites

Parasitism

Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...

, living by hematophagy

Hematophagy

Hematophagy is the practice of certain animals of feeding on blood...

 off the blood

Blood

Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 of rodent

Rodent

Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

s. It is the most widely spread of its genus, having originated in Europe but which has been transported to temperate regions all over the world.

Description

Nosopsyllus fasciatus has an elongated body, 3 to 4 mm in length. It has a pronotal ctenidium

Ctenidium

Ctenidium may be:* Ctenidium , , a comb-like gill, part of the respiratory system of gastropods and bivalves* Ctenidium, , a row of peg-like spines in some insects...

 with 18 to 20 spines (on the first thoracic tergite) but lacks a genal ctenidium. The northern rat flea has eyes and a row of three setae below it on the heads. Both sexes have a prominent tubercle on the front of the head. The hind femur has 3 to 4 bristles on the inner surface.

Pathology

Though the northern rat flea primarily parasitises the Norway rat Rattus norvegidus, it has occasionally been observed feeding on humans and wild rodents. It is a minor vector for plague and is known to be a host of the rat tapeworm Hymenolepis diminuta in South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

, Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

.