Insecta Siphonaptera

Most Active



Warm, humid conditions are preferred. Fleas often enter a building on dogs and cats, and are then deposited in carpeted areas, in the garden, and under the building. The immature stages (eggs and larvae) are found in areas where pets feed and rest, e.g. carpets, bedding, blankets. Fleas are able to survive several months without feeding.

Life cycle

The adult female lays a batch of eggs after each blood feed. Larvae are maggot-like and legless. They feed mainly on skin scales or undigested blood excreted by the adults. The larvae undergo 4 moults prior to pupating in a silken cocoon. Development from egg to adult may take as little as 18 days to more than a year, depending on conditions. Pupae are able to remain dormant for several months, with the emergence of the adult stage often triggered upon detection of vibrations (e.g. when a person enters a house which has been unoccupied for some time).


Considered parasites which feed on the blood of warm-blooded animals, including humans. Bites often appear in clusters on the lower limbs. The flea injects an anti-coagulant during feeding, to prevent blood clotting. This can cause acute irritation, and scratching may often lead to secondary infection. Fleas may also transfer parasites, e.g. tapeworms.


Fleas must be treated both on and off the host. Treat bedding, carpets, soft furnishings and outdoor areas with barrier sprays or granules. See a veterinarian for advice on flea control products for pets.

Prevention Checklist

  • Ensure animal bedding and surrounding areas are thoroughly and regularly cleaned, especially over the summer.
  • Wash dog blankets in bleach and air regularly.
  • Vacuum carpets and furniture (freeze the vacuum bag after use).

General Overview of species

The most common pest species is the cat flea, Ctenocephalides felis. This is found on both cats and dogs. Other flea species attacking humans (the dog flea and the human flea) are rare. Fleas are light brown to mahogany, 2 – 8 mm long, wingless and laterally flattened.