Size
1.5 mm - 10 mm in length but most are shorter than 5 mm.

This insect order is fairly small, having some 2,380 species known worldwide and only about 90 species represented in Australia.  Adult fleas are blood suckers, the majority feeding on mammals (eg dogs, cats, pigs) and some feeding on birds.

Life cycle
Adult males and females, both blood suckers, may live between 100 and 500 days and can survive up to 4 months without food.  The adult female usually lays 4 – 8 eggs after each blood meal.  Eggs usually hatch within 2 to 14 days.  The feeding period for flea larvae is usually 15 days but may be as long as several months in adverse conditions. 

Larvae feed on available organic matter in the form of crumbs, human skin scales and other debris accumulated in carpets, pets bedding, cracks in floor boards, lawns, gardens and sub-floor soil.

When feeding is complete, the larvae usually spin a cocoon, to which adhere particles of dust, soil and the like, which acts as an effective camouflage.  The larvae pupate within the cocoon and the pupal stage may last for several days, or up to a year in some cases.  The entire flea life cycle may take as little as 18 days or up to 18 months in cases where no disturbance has occurred. 

Some flea species are very widespread and as a result of their biting habit, which may cause severe irritation, and their role in disease transmission, the group has justly earned a reputation of being extremely important in the medical and public health context.

When conditions favour flea growth and development, populations can be so great that references to a 'flea plague' are not uncommon.  The management of a flea infestation can be complex and will be difficult to achieve without the assistance and co-operation of the occupants of the building concerned. A sound understanding of the biology of fleas is an important prerequisite to effective control.

Buildings unoccupied for long periods may suddenly seem to come alive with fleas immediately the occupants return.  The significant pest status that fleas have achieved is largely attributable to their 'biting' (piercing and sucking) habit,
which may cause mild to severe irritation or serve to transmit diseases.

Most flea bites occur around the ankles and lower legs. Great variations in the degree of irritation exist between individuals. The irritation, which can persist for days, is due to the injection of saliva which acts as an anticoagulant. Typically, a cluster of bites may occur, and these usually develop into a small red spot, surrounded by a reddish halo but seldom with any swelling.  In Australia it is the frequency of bites, which may occur indoors or outdoors, that can annoy and irritate to the extent where Pest Management measures are sought.

The flea species that are important as pests include:
Cat flea (Ctenocephalides felis).  The cat flea is perhaps the most common pest flea currently encountered.  In addition to cats, it is known to attack dogs, rats, humans and other mammals.

Dog flea (Ctenocephalides canis).  The dog flea is very similar in appearance to the cat flea but seems to be less commonly encountered.  It also attacks a wide range of mammals.

Human flea (Pulex irritans).  This species is becoming much less associated with humans since the advent of the vacuum cleaner and other aids to better housekeeping.  It also attacks dogs, pigs, rats and mice. It is often encountered in piggeries.

Flea Management
Effective flea management relies on the well-directed application of insecticides and insect growth regulators, backed up by procedures that the client undertakes to complete in order to help make the environment less suitable for the development of the fleas.

Cleanliness is an important prerequisite to flea management.   All floor areas should be thoroughly and frequently washed, swept or, in the case of carpets, vacuumed or steam cleaned.  Particular attention should be paid to less disturbed areas eg carpet edges and under furniture.  Areas that may harbour eggs, larvae, pupae or adults should be thoroughly cleaned, including upholstered furniture and, in particular, areas favoured by pets for resting or sleeping.

The contents of the vacuum cleaner bag should be incinerated or sprayed with an aerosol insecticide.  Keeping pets outside may reduce flea concerns indoors, but their presence may still be obvious outdoors.  Subfloor areas should, where possible, be made inaccessible to pets and other animals, as they often offer a very suitable environment for breeding fleas.

Pets should be treated at the same time as the premises.  Pet owners should limit their pets interaction with untreated pets and seek professional advice from their Vet in relation to be best flea control products for their pest/s.

As carpets and rugs must be treated indoors, the choice of an insecticide with a low mammalian toxicity is highly desirable.  Indoors, all surfaces should be treated that may offer a harbourage to eggs, larvae, pupae and adults.  It is advisable to wet outdoors and sub-floor areas prior to the insecticide application, as this will assist the spray to penetrate into the dry soil.

The liquid application to all surfaces is often enhanced by the addition of an IGR (Insect Growth Regulator) to the appropriate liquid application.  Compounds that disrupt normal development so that the insect dies or the adults become sterile.
Once the insecticide application has been completed it is advisable to have activity in every room, every day for the following 21 days in order to keep the life cycle active as the liquid insecticide application cannot penetrate the eggs or affect the pupae.