The body of Ctenocephalides felis is flattened laterally for ease of movement between the hairs of the host. Note small size of head in relation to long powerful hind legs allowing jumps of up to 30cm horizontally and 20cm vertically. Extended jumps are possible due to a protein, resilin, stored in the pleural exoskeleton for release through the hind legs. After leaping the flea tumbles forward with its legs extended like grappling hooks.
(Approx. X25)

Cat Flea head showing small round ocellus (simple eye). The mouthparts of the flea are modified for piercing and sucking - the maxillary palps are seen on the left. One antenna is lying in a deep lateral groove to the right of the eye. A group of backwardly-directed spines above the maxillary palps is called the genal ctenidium.

(Approx. X225)

Higher magnification of the genal ctenidium. The name for this structure is derived from the Greek word for comb (ctenidi) and it deters flea removal by the host.

Approx. X340

After leaping at its host the flea tumbles forward with its legs extended. The pretarsus terminates in two strong claws for grasping host hair and are used like grappling hooks.

(Approx. X750)