Surveys of fleas collected from dogs in Europe, North America and Australia repeatedly find Ctenocephalides felis in the large majority of cases, with the dog flea a minority or absent. The two are separated on details of head shape and the spines of the genal comb, which is why the misattribution persists in casual identification.
The jump is the flea's most examined feature. Energy is stored by compressing a pad of the elastic protein resilin in the thorax and released suddenly, and high-speed video published in 2011 showed that force is transmitted to the ground through the tibia and tarsus, the lower leg, rather than the trochanter as previously supposed. Accelerations reached are on the order of a hundred times gravity.
Because eggs are laid on the host but fall off, most of a flea population at any moment is not on the animal at all but in carpet, bedding and floor cracks as eggs, larvae and pupae.