What do lice and fleas look like? - briefly
Lice are tiny, wingless insects about 2–4 mm long, flattened, cigar‑shaped, with six short legs and a gray‑to‑brown coloration. Fleas measure roughly 2–5 mm, are laterally compressed, dark brown, and possess enlarged hind legs that enable rapid jumps.
What do lice and fleas look like? - in detail
Lice are tiny, wingless insects measuring 2–4 mm in length. Their bodies are flattened laterally, facilitating movement through hair shafts. The head bears a pair of short antennae and compound eyes, though some species have reduced eyes. Mouthparts form a piercing‑sucking stylet used to feed on blood. The thorax supports three pairs of legs, each ending in strong claws adapted for grasping hair. Color ranges from pale gray to brown, often matching the host’s hair. Abdomen segments are clearly defined, with a smooth, glossy exoskeleton.
Fleas are slightly larger, typically 2–5 mm long, and exhibit a laterally compressed, flea‑shaped silhouette. Their bodies are covered with fine, backward‑directed hairs that reduce friction during jumps. The head is small, bearing short antennae concealed beneath the pronotum. Large, robust hind legs end in a series of spines called “pulvilli,” enabling extraordinary leaping ability. Forelegs are equipped with tiny claws for clinging to host fur. Color varies from reddish‑brown to dark brown, sometimes with a light stripe along the dorsal side. The abdomen is segmented, ending in a short, tapered tip.
Key visual differences:
- Size: Lice 2–4 mm; fleas 2–5 mm, often slightly larger.
- Body shape: Lice flattened side‑to‑side; fleas laterally compressed and streamlined.
- Leg structure: Lice have three pairs of equal legs; fleas possess disproportionately large hind legs for jumping.
- Claws: Lice claws are small, adapted for hair; fleas claws are larger, suited for fur.
- Coloration: Lice tend toward gray‑brown tones; fleas display reddish‑brown hues with possible dorsal striping.