How do rat fleas look? - briefly
Rat fleas are tiny, wingless insects measuring 1–3 mm, with a dark brown, laterally flattened body and long, powerful hind legs adapted for jumping. Their heads are small, eyes reduced, and antennae short, giving them a smooth, streamlined appearance.
How do rat fleas look? - in detail
Rat fleas are small, laterally compressed insects measuring 1.5–3 mm in length. Their bodies are dark brown to reddish‑black, with a glossy exoskeleton that reflects light when the flea moves. The head is narrow, bearing a pair of short, segmented antennae and large, compound eyes that dominate the anterior region. Mouthparts form a piercing‑sucking proboscis, adapted for penetrating the host’s skin and extracting blood.
Key morphological features:
- Thorax: robust, bearing three pairs of legs; each leg ends in a strong, backward‑pointing claw that enables rapid jumps.
- Legs: elongated, with rows of tiny spines (setae) that increase traction on fur.
- Abdomen: segmented, slightly flattened, containing the digestive tract and reproductive organs; the ventral surface is smoother than the dorsal side.
- Wings: absent; fleas are wingless, relying on jumping ability for locomotion.
- Sexual dimorphism: females are generally larger, with a more expansive abdomen to accommodate eggs; males possess more prominent genital claspers.
Life‑stage appearance differs:
- Egg: oval, white, 0.5 mm, smooth surface, laid on the host or in the environment.
- Larva: worm‑like, 2–5 mm, pale, without legs, covered in short hairs; molts twice.
- Pupa: encased in a silken cocoon, dark brown, 4–7 mm; remains dormant until stimulated by host vibrations or heat.
- Adult: as described above, fully equipped for blood feeding and rapid movement.
Overall, rat fleas exhibit a compact, hardened body, powerful hind legs for jumps up to 150 mm, and specialized mouthparts that facilitate hematophagy. Their coloration and morphology provide camouflage within the host’s fur, while the absence of wings underscores their adaptation to a parasitic lifestyle.