Xenopsylla cheopis probably originated in Egypt, as a parasite of gerbils and grass rats.
It has been carried around the world by ships’ black rats (Rattus rattus) and now has a cosmopolitan distribution.
It is frequently also found on the brown or common rat (Rattus norvegicus).
There are approximately 2,500 species of flea worldwide, of which 62 are found in Great Britain.
95% of flea species parasitise mammals. The remainder parasitise birds.