Fleas bite animals and humans in order to feed on their blood. These bites usually appear as small red bumps that can be extremely itchy and uncomfortable. Bites often appear in small groups or clusters. In addition to this discomfort caused by the bites, fleas can carry and transmit bacteria and viruses through these bites. If you are bitten, clean the bite with warm water and soap and ice the location to lessen swelling. You can also use anti-itch creams to lessen the discomfort. If at any time you feel that the bite is serious, seek medical help as soon as possible.