Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that survive as external parasites of mammals and birds. Fleas live by consuming blood or hematophagy, from their hosts.Encyclopedia Entry for Fleas :Fleas. Fleas prefer to live on dogs and cats. They may also be found on humans and other warm-blooded animals. Pet owners may not be bothered by fleas until their pet has been gone for a long period of time. Fleas look for other sources of food and begin to bite humans. Bites often occur around the waist, ankles, armpits, and in the bend of the elbows and knees.Symptoms of flea bites include: Small red bumps, often three bumps together, that are very itchy Blisters if the person has an allergy to flea bites Located most often on the arms, legs and places where clothes fit close to the body, such as the thighs and waist.Usually, a diagnosis can be made when the health care provider examines the skin where the bites are. Questions may be asked about contact with animals such as cats and dogs. In rare cases, a skin biopsy is done to rule out other skin problems.You can use an over-the-counter 1% hydrocortisone cream to relieve itching. Antihistamines you take by mouth may also help with itching.Scratching can lead to a skin infection.Prevention may not always be possible. The goal is to get rid of the fleas. This can be done by treating your home, pets, and outside areas with chemicals (pesticides). Small children should not be in the home when pesticides are being used. Birds and fish must be protected when chemicals are sprayed. Home foggers and flea collars do not always work to get rid of fleas. If home treatments do not work, you may need to get professional pest control help.Pulicosis; Dog fleas; Siphonaptera.Flea Flea Flea bite - close-up Flea bite - close-up.Habif TP. Infestations and bites.