How do bed bugs, ticks, and fleas look? - briefly
Bed bugs are flat, oval, reddish‑brown insects about 4–5 mm long; ticks are small, round or oval arachnids ranging from 2 mm to over 1 cm, featuring a hard scutum and prominent legs; fleas are tiny, wingless, dark‑brown insects roughly 2–3 mm, laterally compressed with powerful hind legs for jumping.
How do bed bugs, ticks, and fleas look? - in detail
The visual characteristics of common ectoparasites differ markedly, allowing reliable identification in field or laboratory settings.
Bed bugs are oval, flattened insects measuring 4–5 mm in length when unfed and expanding to about 7 mm after a blood meal. Their coloration ranges from light brown to deep mahogany, often displaying a reddish hue post‑feeding. The dorsal surface bears a distinctive, pale‑colored, hour‑glass marking on the thorax. Antennae consist of five segments, and the mouthparts form a slender, needle‑like proboscis adapted for piercing skin. Legs are short, each bearing three tarsal segments with a small claw.
Ticks are arachnids, typically 3–5 mm in diameter as unfed nymphs, enlarging to 10 mm or more when engorged. The body comprises two main sections: the anterior capitulum, housing the mouthparts, and the posterior idiosoma, covered by a hard or soft shield (scutum) depending on species. Color varies from reddish‑brown in adults to pale tan in larvae. Legs are eight in number, long relative to body size, each ending in a claw that facilitates attachment to host hair or fur. Some species exhibit festoons—small rectangular plates—along the posterior margin.
Fleas are laterally compressed, wingless insects about 2–3 mm long. Their bodies appear dark brown to black, with a glossy, silvery sheen due to dense setae. The head is small, equipped with large, geniculate (bent) hind legs adapted for rapid jumping. Antennae are concealed within grooves on the head, rendering them invisible without magnification. The thorax bears a series of bristles, and the abdomen is segmented, expanding after blood ingestion.
Key distinguishing features:
- Bed bugs: oval, flat, hour‑glass marking, short legs, proboscis.
- Ticks: eight legs, scutum or soft integument, noticeable capitulum, engorgement size change.
- Fleas: laterally flattened, powerful hind legs for jumping, concealed antennae, glossy dark body.