Pest profile

Oriental Rat Flea

Xenopsylla cheopis · Siphonaptera: Pulicidae[2]

The oriental rat flea lives mainly on rats and is best known as a carrier of the plague bacterium.[1]

Oriental rat flea adult, a slide-mounted brown flea seen from the side, with a 0.5 mm scale bar
Oriental rat flea adult, a slide-mounted brown flea seen from the side, with a 0.5 mm scale bar. Photo: Daniel J. Drew, public domain (CC0), via Wikimedia Commons

How to identify it

  • Adults are brown, flattened side to side and 2 to 4 mm long, with long, spiny legs.[1]
  • Unlike cat and dog fleas, it has no comb of bristles below the eyes or behind the head.[1]

Look-alikes

Look-alikeHow to tell them apart
Cat fleaThe cat flea has both bristle combs; the oriental rat flea has neither.[1]

Where it lives

It occurs worldwide wherever its hosts, rats and other small mammals, live; temperature and humidity limit it.[1]

US map: public records from 2 states since 1990 (GBIF).

Biology and life cycle

Females lay up to 300 to 400 eggs in a lifetime, mostly in the host's nest rather than on the host.[1]

It prefers rats but also feeds on cats, dogs and wild mammals; people are accidental hosts.[1]

Health risk

It carries plague bacteria and Rickettsia typhi, the cause of flea-borne typhus, and can transmit tapeworms.[1]

Control

Traps and physical control

Managing it means removing rats and other small host mammals, generally by trapping and poisoning.[1]

Pesticides

Insecticides in burrows and runways help, but resistance is making them less effective.[1]

Common questions

Does the oriental rat flea carry plague?
Yes; it's best known as a carrier of the plague bacterium, Yersinia pestis.[1]
Why do rat fleas come back after treatment?
Fleas also live in host nests, which can reinfest nearby buildings if not managed.[1]

Sources

  1. University of Florida IFAS Extension (Featured Creatures), “Oriental Rat Flea, Xenopsylla cheopis (EENY-775).” edis.ifas.ufl.edu/publication/IN1330 (accessed 2026-10-06)
  2. iNaturalist, “Xenopsylla cheopis taxon page (order and family).” www.inaturalist.org/taxa/271312 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.