Fleas (Parasite) are not only a nuisance to humans and their pets, but can cause medical problems including flea allergy dermatitis (FAD), secondary skin irritations and, in extreme cases, anemia, tapeworms, stomach flu. Fleas can transmit murine typhus (endemic typhus) fever among animals and from animal to humans. Also, fleas can transmit bubonic plague and any other disease from human to rodent and from rodent to humans. Tapeworms normally infest in humans in severe cases. Although bites are rarely felt, it is the resulting irritation caused by the flea salivary secretions that varies among individuals. Some may witness a severe reaction (general rash or inflammation) resulting in secondary infections caused by scratching the irritated skin area. Others may show no reaction or irritation acquired after repeated bites over several weeks or months. Most bites usually found on the ankles and legs may cause irritation or pain lasting a few minutes, hours or days depending on one’s sensitivity. The typical reaction to the bite is the formation of a small, hard, red, slightly-raised (swollen) itching spot. There is a single puncture point in the center of each spot. (Ants and spiders leave two marks when they bite. Mosquitoes, bees, wasps and bedbugs cause a large swelling or welt.