How does a human flea look? - briefly
The human flea (Pulex irritans) is a tiny, dark‑brown insect measuring 1.5–3 mm in length, with a laterally flattened, compact body, long hind legs adapted for jumping, and a row of stiff setae near the head. Its thorax and abdomen are covered in fine hairs that give a slightly fuzzy appearance.
How does a human flea look? - in detail
The human flea (Pulex irritans) measures 1.5–3 mm in length, slightly larger than the cat flea. Its body is laterally compressed, giving a flattened appearance that facilitates movement through clothing and hair. The exoskeleton is a dark reddish‑brown color when engorged and a lighter tan when unfed. The head is small, equipped with short, segmented antennae that end in a pair of sensory pits. Compound eyes are reduced, appearing as tiny dark spots on the lateral sides of the head.
The thorax bears three pairs of legs, each ending in a claw with a small basal tooth that enables the flea to grasp hair shafts. Leg segments are slender, and the hind legs are proportionally longer, providing powerful jumps of up to 150 mm. The abdomen consists of ten visible tergites, each bearing fine, backward‑pointing setae that give the flea a somewhat bristly texture. When feeding, the abdomen expands dramatically, becoming distended and bright red due to blood intake.
Key morphological features:
- Size: 1.5–3 mm, flattened dorsoventrally.
- Color: tan (unfed) to reddish‑brown (fed).
- Head: short antennae, reduced compound eyes.
- Legs: three pairs, each with a claw and basal tooth; hind legs adapted for jumping.
- Abdomen: ten tergites with setae, expands markedly after a blood meal.
Male and female fleas are similar in overall shape; females are slightly larger to accommodate egg development. The body surface is covered with a thin waxy layer that reduces water loss, contributing to the flea’s resilience in varied environments.