House flies can be easily identified by the four dark, longitudinal stripes on top of the thorax, or middle body region. They vary in length from l/8-l/4 of an inch. Their mouth parts are adapted for sponging up liquids; they cannot bite. These flies can only ingest liquid food. They feed on attractive solid food by regurgitating saliva on it. The saliva liquifies the solid material which is then sponged up with the proboscis. They require water since they are continually salivating and voiding liquids. Fly specks seen on many surfaces visited by house flies are the excreted wastes.