How can you tell if your cat has fleas?

A cat infested with fleas may scratch more than usual or groom itself obsessively – or may not.
You may also find small black/brown specks on your pet’s skin or bedding. These specks look like tiny coffee grounds and are commonly called “flea dirt.” Flea dirt is the feces of adult fleas and is actually the digested blood of the host. When the dark particles get wet, the red color returns, which may help with identification.
But some cats seem to tolerate fleas in their fur with out much irritation.
In addition to all the skin problems that fleas can cause, fleas can use our cats as transportation around our home and lay their eggs in our carpets, couches and other places where they will hatch and potentially create a very unpleasant flea infestation. While treating dog fleas is very different from cat flea treatment, it’s very important to follow a step by step process for getting rid of these pests on your pets. If you have found signs of fleas on your cat then you need to take steps to control the fleas.You may not see the cat fleas, but flea dirt is a sure sign your cat has them.5 Natural Ways to Get Rid of Fleas on Cats- a great list of natural flea remedies for cats!
Cat Fleas, Ctenocephalides felis, are wingless flattened insects. Adult cat fleas can range in colour from quite light reddish brown to quite dark almost black. It is likely fleas adapt to the colour of their hosts.Cat fleas are great athletes with huge back legs well suited to jumping. Leaps of over a meter have been reported but most fleas leaps will not exceed the height of a cat, under a foot.Treating the cat will get rid of the fleas and treating the bedding will get rid of the eggs larvae and some pupae. (Pupae are tough little guys and are difficult to kill.)Although cat fleas are quite small. 1-3 millimeters, they can easily be seen. The best place to look for them is at the base of the cat's tail, between the legs on the belly and in spots that are hard for the cat to reach.Because fleas are flattened and their body hard and slippery, they easily move between hairs, or clothing, helped by their backwards pointing bristles. Anyone chasing a flea in a cat knows how agile and quick they can be. This also allows the flea to move quickly in carpets or bedding.The adult cat flea is only one of the forms a flea can take. If you have adult fleas you most certainly have flea eggs, flea larvae, flea dirt, and flea pupa.Spot on Flea treatments is an effective way of controlling fleas on cats. A drop of insecticide is placed between the cat's shoulderblades. Gradually the flea treatment migrates over most of the cat's body because of oils on the skin of the cat and the active grooming a cat does.These systemic medications appear to be quite safe but have not been around long enough for long term effects to be completely identified. Since they work by interrupting a process that is specific to the flea, usually preventing an enzyme or protein from being made they are very specific to fleas.These pills are not insecticides and do not kill fleas. Instead they disrupt the flea life cycle. Insect growth regulators prevents the flea from properly completing its lifecycle and causes the flea to eventually die. They are flavoured and some cats will take them with no argument at all. Others need the usual subterfuge to administer the medicine.Some insect growth regulators have been developed which are sprayed in areas where the cats spend time. This does not kill fleas on contact but rather prevent the flea from completing its life cycle.