Adult fleas are normally 1-8mm long, brownish in colour, no wings but muscular legs adapted for jumping. The potential life span of a female flea is two years during which she can lay up to 1000 eggs.
The cat flea (Ctenocephalides felis) causes most flea infestations. The significance of this is explained by the increased number of pets being kept and the tendency for their beds to be neglected during cleaning. Wall to wall carpeting also provides a relatively undisturbed environment for flea larvae to develop.
Fleas are objectionable because of the bites they inflict and because of the social stigma attached to humans with flea infestations. Flea bites are identified as a tiny dark red spot surrounded by a reddened area. The intensely irritating bite persists for one or two days.