To combat fleas, it is important to understand their life cycle. There are 4 stages to the flea life cycle, known as metamorphosis.

The image below shows a break up of the population of fleas & their life cycle. As you can see, only 5% are actually adult fleas which would live on your cat, the remainder are found in the environment in the form of eggs (50%), larvae (35%)  & pupae (10%). It is absolutely vital to treat both your pet & hour environment (home & garden) if you are to combat fleas.

1) Adult flea: The adult flea emerges when it is stimulated by environmental factors such as vibrations, warmth or breath of the host. The flea can come out of it's cocoon within seconds of stimulation. The lifespan of an adult flea is around 2 - 3 months. The adult flea is around 1.5 - 4mm long, and dark brown or black in appearance. Adults suck blood from their host. Adult fleas begin laying eggs within 36 - 48 hours of their first blood meal. A female flea consumes up to 15 times her body weight in blood per day.

2) Egg: At .5mm in length, flea eggs are barely visible to the human eye, the female flea lays approximately one egg per hour. The flea egg is whitish, smooth & dry & easily falls off the coat into the environment. Flea eggs hatch in around 1 - 10 days, depending on conditions. Flea eggs & flea droppings are often found together. When the cat scratches the eggs along with the droppings fall off the cat. The droppings provide food to the larvae when they hatch. The eggs & droppings together have the appearance of salt & pepper.

Environmental conditions such as humidity, light & temperature determine how quickly & how many flea larvae hatch from flea eggs. The lower the temperature, the fewer larvae will hatch. Optimal conditions for flea larvae to hatch are 70% & higher & temperatures of 21 - 32 degrees C (70 - 89 degrees F).

Flea eggs fall off the cat when it jumps, scratches, moves & sleeps. Eggs are found all over the home, but in their highest concentrations in your cat's preferred spots such as bedding.

3) Larvae: The larvae are vermiform (maggot like) like in appearance & up to 6mm long, flea larvae avoid light by residing deep in carpet fibres, under furniture & rugs & in crevices. At this stage they have no legs or eyes, but have chewing mouth parts.  Flea larvae feed on adult flea excrement, food debris & dead skin.

4) Pupae: This is the transition stage between larvae & adult flea. After approximately 7-18 days the flea larvae pupate.  It takes approximately 7 - 10 days for the larvae to develop into a flea, although it may be some time before the flea emerges from it's protective cocoon.  They are at their most resilient as pupae, and resistant to  insecticides.

The flea larvae spins a sticky, protective silken (produced by the saliva of the larvae) outer cocoon, covered with particles of debris such as dust, hair, lint etc.   The pupae are found in carpet fibres, crevices etc., and are virtually undetectable.

Treat Your Cat:

There are several methods of flea control for cats: These products vary in price & effectiveness. Flea collar, shampoo, flea combs, spray, tablets, powders, insect growth regulators & topical treatments. Flea collars: There are many different types of flea collar on the market. Some are insecticide only & work by killing adult fleas on the cat. Other flea collars contain IGR's to kill the eggs & larvae. Flea collars often only kill fleas on the cat's head & neck, but fleas further down the body survive.

Shampoo/Dips: Flea shampoos contain insecticides which kill adult fleas.

Flea Combs: Flea combs aren't overly effective, only removing 10 - 50% of fleas on your cat. If you wish to use this method place a small bowl of water with some detergent in it close by & drop the fleas into the bowl. This will drown the fleas. Placing a small amount of petroleum jelly onto the teeth of the comb will help the fleas stick to it.

Flea Powders: Flea powders will kill adult fleas on the cat. Powders may cause the cat's coat to dry out & also may be irritating to the cat's oral & respiratory mucosa.

Oral suspensions: Program® is given to cats via an oral suspension once a month. The product is added to the cat's food & is absorbed into the bloodstream. When a flea bites a cat treated with Program it ingests the active ingredient (lufenuron), which is passed to her eggs & prevents them from hatching. As this product only prevents eggs from hatching, an appropriate adulticide will also be needed to kill adult fleas. Seek advice from your veterinarian before using more than one product on your cat. It is also extremely important to speak to your veterinarian if you are considering treating a pregnant or nursing cat. They will be able to recommend the safest treatment for your cat.

Spot on treatments:  Topical adulticide. There are several effective products on the market which are administered via liquid form to the cat's shoulders. These are available through your veterinarian or online pet product store.  These products are very effective for killing adult fleas on your cat. The active ingredient varies from product to product. Application is generally once a month.

When applying a flea product to a cat it is important to follow the instructions on the packet to the letter.   Cats are extremely sensitive to chemicals & if you are using one than one product your cat may be exposed to too many toxins, resulting in sickness or death.

Some of the most effective & popular topical flea control products used on cats (and dogs) include Advantage, Revolution & Frontline.

Revolution also kills worms (except tapeworm), so makes life a bit easier for pet owners, according to the Bayer site, Advantage cat flea control, also kills flea larvae in the pet's environment too.

Cat Flea Sprays: There are some effective cat flea sprays on the market. Frontline make such a spray. Wear rubber gloves while applying the spray to your cat while ruffling the coat. Avoid contact with the eyes & mouth.

Warning: Don't ever use flea products designed for other pets on your cat & ALWAYS follow the dosage chart on the back of the packet.

Treat The Environment:

IGR's: (insect growth regulators) disrupt the cycle of the flea. They prevent eggs from hatching, kill larvae & prevent adult fleas from reproducing. These most often come in as a  bomb/spray.

A pest controller should be able to spray your house & garden for fleas. It is important to specify that you have cat(s) living in the house, so they can use a suitable spray which is safe for pets.

Wash rugs, cat bedding etc., in the hottest possible cycle.

Frequent vaccuming will also remove fleas & their eggs. One useful tip is to put a flea collar in your vacuum cleaner bag. When vacuuming, pay extra attention to corners, skirting boards, under furniture & any other nooks & crannies. Also vacuum furniture, curtains etc. This is where the larvae love to hang out, eating dust & debris, so it is vital that you thoroughly vacuum. Once you have vacuumed, clean out the bag & dispose of carefully. Ensure that every time you vacuum, you empty it out to prevent any fleas escaping.

Treat Outdoors:

Fleas can infest your garden & outdoor buildings too, so while you are treating your cat & house, also pay attention to your garden. Spray areas your pet tends to hang out, and if it has bedding in the garden, bring it in & wash it. You may wish to flea bomb any outdoor buildings you have, especially if your cat hangs out there.

Long term flea control

Regular application of a good quality flea control on your cat is the best method of flea control. Ensure your cat's bedding is regularly washed.

Related articles:

Treating flea bites on humans