As few as one or two bites can cause severe itching and scratching in allergic pets. Cat fleas are the most common fleas on dogs and cats. They also infest raccoons, oppossums and coyotes. Flea life cycle. Cat fleas do not normally live on humans, but do bite people who handle infested animals.
Flea bites cause small, red, itchy bumps, usually on the ankles and lower legs.
People with allergies to flea bites suffer from hives, rashes or generalized itching. Allergic reactions usually appear 12 to 24 hours after a bite, and may last a week or more. Fleas that have fed on rodents may transmit diseases, including plague and murine typhus. For this reason, avoid close contact with wild rodents such as squirrels, rats and prairie dogs. Their fleas can bite you and may transmit disease.