The Life Cycle of a Flea Explained | Veterinary Prescriber
The Life Cycle of a Flea Explained
The cat flea thrives in the UK, and despite the name it is the most common cause of flea infestations in both cats and dogs. Because of this, in this blog when we’re talking about the ‘life cycle of a flea’, we are talking about the life cycle of a cat flea and hence the dog flea life cycle at the same time.
Flea bites can cause discomfort and are a common cause of allergic dermatitis in dogs, cats and other pets, but in addition fleas can lead to the presence of certain feline tapeworms.
Cat fleas cannot live and reproduce on people, but they can bite humans, leading to skin irritation. They can also lead to infections in humans, notably causing illnesses such as cat scratch fever.
The Life Cycle of a Flea Explained
The life cycle of a flea - step by step
Having a good understanding of the life cycle of a flea is essential to successful flea control. Adult fleas can begin to lay eggs within 24–48 hours of their first blood meal, and they normally lay around 24–28 eggs per day, mostly at night. Once laid, the life cycle of a flea follows this basic course:
Flea eggs are not sticky and can fall off the animal as it moves or grooms itself. They hatch 1–10 days later, depending on temperature and humidity.
The resulting larvae are free-living and feed on adult flea faeces containing large amounts of incompletely digested blood. The larvae also feed on organic debris and on flea eggs in the environment.
Flea larvae move away from direct sunlight, preferring darker, more humid areas in their environment – e.g. deep into carpet fibres, animal bedding, soft furnishings, floorboard cracks etc. Outside they may go under grass, branches, leaves or soil. Flea larvae are very susceptible to heat and drying out and need a moist environment to survive.
In the following few days after hatching larvae undergo two moults before spinning a silken cocoon and moulting to the pupal stage.
This pupal stage can end within 1–2 weeks, with the next stage in the life cycle of a flea being adulthood.
Flea pupae can remain viable for several months. Debris from the environment can stick to the cocoon, which makes them more resistant to adverse environmental conditions and insecticides. As a result an infestation can still be established even if the flea has gone without a suitable host for some time.
Pupae hatch in response to heat and movement, and so can be reactivated by the new arrival or return of possible hosts.
Adult fleas that have emerged from dark areas move towards a light source. They then jump when the light source is suddenly and temporarily interrupted or if they detect vibrations that indicate a potential host.
If the newly emerged adults do not immediately acquire a host, they can survive several days before requiring a blood meal.
Once on the host, the flea starts to feed within seconds or minutes, and mates within 8 to 24 hours.
Under most household conditions, the life cycle of a flea can be completed in 3–8 weeks.
The speed of growth and mating inherent to the life cycle of a flea means just a few adult fleas can very quickly lead to larger numbers. The presence of central heating in homes means that today fleas can be active all year round, and the higher temperatures also speed up the life cycle of a flea. Sadly, this means that by the time fleas have been found on your animal, an infestation may have already established itself in their home.
The Life Cycle of a Flea Explained
Managing an infestation
Effective flea control hinges on preventing fleas from laying eggs by simultaneously treating all the susceptible animals in a household with a product designed to kill adult fleas.
It may take several months to effectively control an infestation, but don’t forget that you can ask your vet, or a qualified veterinary medicines advisor at a pet store (a Suitably Qualified Person / SQP in the UK) for advice on choosing a suitable flea treatment for your pet. Lastly, remember to read the package leaflet to make sure the treatment is used correctly for best effect.
The Life Cycle of a Flea Explained
Eliminating flea life stages in the environment
Anything that helps to reduce the number of eggs and larvae will in turn reduce the number of pupae in the environment, which in turn will reduce the time needed to bring an infestation under control. It will also reduce the number of flea bites that pets and owners receive, and the risk of becoming ill as a result of a bite.
So, what can you do to eliminate a flea infestation?
Treat your animals - to break the life cycle and effectively end a flea infestation - and don’t forget that the life cycle of a cat flea is also the dog flea life cycle - you will first need to treat all vulnerable animals with an appropriate flea medication. There are may different options available - some you can buy from supermarkets or pet shops, others available from your vet. Read about flea treatments, including non-prescription products, which usually contain fipronil, here.
Physical cleaning - Vacuuming has been shown to be useful in reducing and killing pupae, eggs and larvae in households, breaking the life cycle of a cat flea. However, vacuuming alone is unlikely to end an infestation.
Washing pet bedding at 60 degrees Centigrade will also help, but please note that there is no evidence that conventional household cleaning products have any impact on flea numbers.
Environmental pesticides – Products designed to kill fleas will reduce larvae and egg numbers significantly if used correctly and in the right places.
Growth regulators - These drugs prevent fleas from developing and entering the next stage of the life cycle of a cat flea. They are frequently included alongside flea parasiticides in pet flea treatments.
Dimeticone – The use of dimeticone in spray form has been developed as an environmentally-friendly alternative to insecticides. It has the advantage of being able to be used if there are pet invertebrates or fish in the household. However, treatment with dimeticone only remains effective for around 3–4 weeks after application.