Genus Pulex is a scientific term that refers to a class of parasitic insects. There are several other synonyms that are used to describe these insects such as the common flea, jigger flea, dog flea, and cat flea. The Genus Pulex typically lives on the blood of various animals and can transmit diseases such as typhus and plague. Pulex irritans is the specific species name that is often mentioned in scientific literature. Although fleas are problematic for animals and humans, they do serve a role in the environment by being a food source for various creatures such as birds and small mammals.