How to prevent and cure infestations of pests specifically fleas and fungus infections.
Ringworm is a fungal infection and is highly contagious to both cats and people. If you detect red lesions (usually but not always in a ring-type pattern), or one or more bald patches on your cat's skin (sometimes accompanied by scabs or scaling i.e. looks a bit like dandruff but isn't), take your cat to a veterinarian. Even a Wood's Lamp (black light), is not 100% reliable in that ringworm doesn't necessarily fluoresce in a lot of cases. So don't assume all is well if nothing shows up with a Wood's Lamp. To be sure, have your cat's veterinarian take skin scrapings, and perform a culture test to confirm a diagnosis of ringworm.
Flea control is a challenge with cats for many reasons, not the least of which is ingestion concerns. From what we've seen on the list these last thirteen or so years, cat livers are ill-equipped to handle the chemicals in flea products such as bombs, foggers, sprays, collars, shampoos, and powders containing insecticides, oils, and other noxious substances. Please be careful with "natural" products as well. Don't assume something that says "natural" is automatically safe for a cat.