The hind pair of legs is modified for jumping.
Fleas are vertically flat like a fish, and can move easily through the hair of a host.
The immature stage or larval stage of the flea looks like a small white worm with a dark head. Flea eggs are small and white. The cooler and drier fall weather brings a reduction in the number of household fleas. The eggs drop off and hatch into tiny, hairy, worm-like larvae. The larvae are usually found where the animal sleeps, along baseboards, in carpets, or on furniture.