Fleas are a wingless parasitic insect that causes direct harm to mammals and birds by biting them for the sole purpose of obtaining food. This is in contrast to other insects that do their harm by competing for food or damaging property.
Fleas have mouthparts that are used to pierce the skin and suck the blood of their hosts.
Climate conditions that the fleas prefer and thrive in are warm and humid. It is also these conditions that favor the laying of their eggs. The typical flea can live anywhere from a few days to several months. Their presence is most prominent in the summer and autumn but can be a year-round problem in warmer climates. The most common flea to afflict households is the cat flea, especially in the East.