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. Larvae pupate and new adults emerge. The new adults seek a host immediately and must get a blood meal to survive and produce eggs.